id
stringlengths
9
16
submitter
stringlengths
1
64
authors
stringlengths
3
36.7k
title
stringlengths
1
382
comments
stringlengths
1
1.15k
journal-ref
stringlengths
1
557
doi
stringlengths
7
153
report-no
stringlengths
1
479
categories
stringlengths
5
125
license
stringclasses
9 values
abstract
stringlengths
6
6.09k
versions
list
update_date
timestamp[s]
authors_parsed
sequence
0707.0730
Bringfried Stecklum
Bringfried Stecklum, Helmut Meusinger, Dirk Froebrich
Herbig-Haro Objects - Tracers of the Formation of Low-mass Stars and Sub-stellar Objects
contribution presented at the 5th Stromlo Symposium, 5 pages, 4 Figures. Accepted for publication in Astrophysics & Space Science
Astrophys.SpaceSci.311:63-67,2007
10.1007/s10509-007-9573-x
null
astro-ph
null
Herbig-Haro objects (HHOs) are caused by outflows from young objects. Since the outflow relies on mass accretion from a circumstellar disk, it indicates ongoing growth. Recent results of infrared observations yielded evidence for disks around brown dwarfs. This suggests that at least a certain fraction of brown dwarfs forms like stars. Thus, young sub-stellar objects might cause HHOs as well. We present selected results of a general survey for HHOs based on DSS-II plates and CCD images taken with the Tautenburg Schmidt telescope. Numerous young objects could be identified due to their association with newly detected HHOs. In some cases the luminosity is consistent with very low-mass stars or close to sub-stellar values. This holds for L1415-IRS and a few infrared sources embedded in other dark clouds (e.g., GF9, BHR111). The question on the minimum mass for outflow activity is addressed.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 07:57:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Stecklum", "Bringfried", "" ], [ "Meusinger", "Helmut", "" ], [ "Froebrich", "Dirk", "" ] ]
0707.0731
Mikhail Zubkov
M.A.Zubkov
$Z_6$ symmetry of the Standard Model and Technicolor theory
Latex, 16 pages
Physics Letters B674 (2009), 325-329
10.1016/j.physletb.2009.03.032
ITEP-LAT/2007-11
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the possibility to continue the $Z_6$ symmetry of the Standard Model to the Technicolor theories. Among the SU(N) Weinberg - Susskind models and the SU(N) Farhi - Susskind models for $N>2$ only the SU(4) Farhi - Susskind model may possess the mentioned symmetry. We also show that the hypercharge assignment of Minimal Walking SU(2) Technicolor model may be chosen in such a way that the additional discrete symmetry is preserved.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 07:58:08 GMT" }, { "version": "v2", "created": "Mon, 23 Feb 2009 09:41:16 GMT" }, { "version": "v3", "created": "Wed, 8 Apr 2009 10:13:22 GMT" } ]
2009-04-08T00:00:00
[ [ "Zubkov", "M. A.", "" ] ]
0707.0732
Alexander Savin
A. M. Savin, M. Meschke, J. P. Pekola, Yu. A. Pashkin, T. F. Li, H. Im, and J. S. Tsai
Parity effect in Al and Nb single electron transistors in a tunable environment
3 pages, 3 figures
null
10.1063/1.2768897
null
cond-mat.supr-con
null
Two different types of Cooper pair transistors, with Al and Nb islands, have been investigated in a tunable electromagnetic environment. The device with an Al island demonstrates gate charge modulation with 2e-periodicity in a wide range of environmental impedances at bath temperatures below 340 mK. Contrary to the results of the Al sample, we were not able to detect 2e-periodicity under any conditions on similar samples with Nb island. We attribute this to the material properties of Nb.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:26:15 GMT" } ]
2009-11-13T00:00:00
[ [ "Savin", "A. M.", "" ], [ "Meschke", "M.", "" ], [ "Pekola", "J. P.", "" ], [ "Pashkin", "Yu. A.", "" ], [ "Li", "T. F.", "" ], [ "Im", "H.", "" ], [ "Tsai", "J. S.", "" ] ]
0707.0733
Jamil Aslam
M. Ali Paracha, Ishtiaq Ahmed, M. Jamil Aslam
Form factors, branching ratio and forward-backward asymmetry in B -> K_{1}ell ^{+} ell ^{-} decays
15 pages, 2 figures
Eur.Phys.J.C52:967-973,2007
10.1140/epjc/s10052-007-0422-4
null
hep-ph
null
We study long-distance effects in rare exclusive semileptonic decays B -> K_{1}ell ^{+}ell ^{-}, K_{1} is the axial vector meson.The form factors, describing the meson transition amplitudes of the effective Hamiltonian, are calculated using Ward identites which are then used to calculate branching ratio and forward-backward asymmetry in these decay modes. The zero of forward-backward asymmetry is of special interest and provide us the precission test of Standard model.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 08:11:09 GMT" }, { "version": "v2", "created": "Wed, 26 Sep 2007 08:27:12 GMT" } ]
2016-09-08T00:00:00
[ [ "Paracha", "M. Ali", "" ], [ "Ahmed", "Ishtiaq", "" ], [ "Aslam", "M. Jamil", "" ] ]
0707.0734
Endre Cs\'aki
Endre Cs\'aki, Ant\'onia F\"oldes, P\'al R\'ev\'esz
Transient NN random walk on the line
25 pages
null
null
null
math.PR
null
We prove strong theorems for the local time at infinity of a nearest neighbor transient random walk. First, laws of the iterated logarithm are given for the large values of the local time. Then we investigate the length of intervals over which the walk runs through (always from left to right) without ever returning.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 08:11:15 GMT" } ]
2007-07-06T00:00:00
[ [ "Csáki", "Endre", "" ], [ "Földes", "Antónia", "" ], [ "Révész", "Pál", "" ] ]
0707.0735
Oliver Burmeister
A. Bunkowski, O. Burmeister, T. Clausnitzer, E.-B. Kley, A. T\"unnermann, K. Danzmann, R. Schnabel
Optical characterization of ultra-high diffraction efficiency gratings
null
Applied Optics Vol. 45, No. 23 5795 (2006)
10.1364/AO.45.005795
null
physics.optics
null
We report on the optical characterization of an ultra-high diffraction efficiency grating in 1st order Littrow configuration. The apparatus used was an optical cavity built from the grating under investigation and an additional high reflection mirror. Measurement of the cavity finesse provided precise information about the grating's diffraction efficiency and its optical loss. We measured a finesse of 1580 from which we deduced a diffraction efficiency of (99.635$\pm$0.016)% and an overall optical loss due to scattering and absorption of just 0.185 %. Such high quality gratings, including the tool used for their characterization, might apply for future gravitational wave detectors. For example the demonstrated cavity itself presents an all-reflective, low-loss Fabry-Perot resonator that might replace conventional arm cavities in advanced high power Michelson interferometers.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 08:33:46 GMT" } ]
2009-11-13T00:00:00
[ [ "Bunkowski", "A.", "" ], [ "Burmeister", "O.", "" ], [ "Clausnitzer", "T.", "" ], [ "Kley", "E. -B.", "" ], [ "Tünnermann", "A.", "" ], [ "Danzmann", "K.", "" ], [ "Schnabel", "R.", "" ] ]
0707.0736
Jean-Philippe Uzan
Thiago S. Pereira, Cyril Pitrou, Jean-Philippe Uzan
Theory of cosmological perturbations in an anisotropic universe
33 pages
JCAP0709:006,2007
10.1088/1475-7516/2007/09/006
null
astro-ph gr-qc hep-ph hep-th
null
This article describes the theory of cosmological perturbations around a homogeneous and anisotropic universe of the Bianchi I type. Starting from a general parameterisation of the perturbed spacetime a la Bardeen, a complete set of gauge invariant variables is constructed. Three physical degrees of freedom are identified and it is shown that, in the case where matter is described by a scalar field, they generalize the Mukhanov-Sasaki variables. In order to show that they are canonical variables, the action for the cosmological perturbations at second order is derived. Two major physical imprints of the primordial anisotropy are identified: (1) a scalar-tensor ``see-saw'' mechanism arising from the fact that scalar, vector and tensor modes do not decouple and (2) an explicit dependence of the statistical properties of the density perturbations and gravity waves on the wave-vector instead of its norm. This analysis extends, but also sheds some light on, the quantization procedure that was developed under the assumption of a Friedmann-Lemaitre background spacetime, and allows to investigate the robustness of the predictions of the standard inflationary scenario with respect to the hypothesis on the symmetries of the background spacetime. These effects of a primordial anisotropy may be related to some anomalies of the cosmic microwave background anisotropies on large angular scales.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 08:56:59 GMT" } ]
2008-11-26T00:00:00
[ [ "Pereira", "Thiago S.", "" ], [ "Pitrou", "Cyril", "" ], [ "Uzan", "Jean-Philippe", "" ] ]
0707.0737
Victor P. Debattista
Victor P. Debattista, Ben Moore, Thomas Quinn, Stelios Kazantzidis, Ryan Maas, Lucio Mayer, Justin Read, and Joachim Stadel
The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks Versus Substructures
35 pages, 13 figures (3 in color). Accepted to ApJ. This version is expanded, with new simulations included in response to referee. Conclusions remain unchanged
null
10.1086/587977
null
astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cold dark matter cosmogony predicts triaxial dark matter halos, whereas observations find quite round halos. This is most likely due to the condensation of baryons leading to rounder halos. We examine the halo phase space distribution basis for such shape changes. Triaxial halos are supported by box orbits, which pass arbitrarily close to the density center. The decrease in triaxiality caused by baryons is thought to be due to the scattering of these orbits. We test this hypothesis with simulations of disks grown inside triaxial halos. After the disks are grown we check whether the phase space structure has changed by evaporating the disks and comparing the initial and final states. While the halos are substantially rounder when the disk is at full mass, their final shape after the disk is evaporated is not much different from the initial. Likewise, the halo becomes (more) radially anisotropic when the disk is grown, but the final anisotropy is consistent with the initial. Only if the baryons are unreasonably compact or massive does the halo change irreversibly. We show that the character of individual orbits is not generally changed by the growing mass. Thus the central condensation of baryons does not destroy enough box orbits to cause the shape change. Rather, box orbits merely become rounder along with the global potential. However, if angular momentum is transferred to the halo, either via satellites or via bars, a large irreversible change in the halo distribution occurs. The ability of satellites to alter the phase space distribution of the halo is of particular concern to galaxy formation simulations since halo triaxiality can profoundly influence the evolution of disks.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 08:53:22 GMT" }, { "version": "v2", "created": "Fri, 13 Jun 2008 01:18:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Debattista", "Victor P.", "" ], [ "Moore", "Ben", "" ], [ "Quinn", "Thomas", "" ], [ "Kazantzidis", "Stelios", "" ], [ "Maas", "Ryan", "" ], [ "Mayer", "Lucio", "" ], [ "Read", "Justin", "" ], [ "Stadel", "Joachim", "" ] ]
0707.0738
Erwan Lanneau
Pascal Hubert, Erwan Lanneau, Martin Moeller
Completely periodic directions and orbit closures of many pseudo-Anosov Teichmueller discs in Q(1,1,1,1)
38 pages, submitted
null
null
null
math.GT math.DS
null
In this paper, we investigate the closure of a large class of Teichm\"uller discs in the stratum Q(1,1,1,1) or equivalently, in a GL^+_2(R)-invariant locus L of translation surfaces of genus three. We describe a systematic way to prove that the GL^+_2(R)-orbit closure of a translation surface in L is the whole of L. The strategy of the proof is an analysis of completely periodic directions on such a surface and an iterated application of Ratner's theorem to unipotent subgroups acting on an ``adequate'' splitting. This analysis applies for example to all Teichmueller discs stabilized obtained by Thurston's construction with a trace field of degree three which moreover ``obviously not Veech''. We produce an infinite series of such examples and show moreover that the favourable splitting situation does not arise everywhere on L, contrary to the situation in genus two. We also study completely periodic directions on translation surfaces in L. For instance, we prove that completely periodic directions are dense on surfaces obtained by Thurston's construction.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 17:44:01 GMT" } ]
2007-07-06T00:00:00
[ [ "Hubert", "Pascal", "" ], [ "Lanneau", "Erwan", "" ], [ "Moeller", "Martin", "" ] ]
0707.0739
Christopher Allan Watson
C. A. Watson, D. Steeghs, T. Shahbaz, V. S. Dhillon
Roche tomography of cataclysmic variables - IV. Starspots and slingshot prominences on BV Cen
16 pages, 13 figures, accepted for publication in MNRAS
null
10.1111/j.1365-2966.2007.12173.x
null
astro-ph
null
We present Roche tomograms of the G5-G8 IV/V secondary star in the long-period cataclysmic variable BV Cen reconstructed from MIKE echelle data taken on the Magellan Clay 6.5-m telescope. The tomograms show the presence of a number of large, cool starspots on BV Cen for the first time. In particular, we find a large high-latitude spot which is deflected from the rotational axis in the same direction as seen on the K3-K5 IV/V secondary star in the cataclysmic variable AE Aqr. BV Cen also shows a similar relative paucity of spots at latitudes between 40-50 degrees when compared with AE Aqr. Furthermore, we find evidence for an increased spot coverage around longitudes facing the white dwarf which supports models invoking starspots at the L1 point to explain the low-states observed in some cataclysmic variables. In total, we estimate that some 25 per cent of the northern hemisphere of BV Cen is spotted. We also find evidence for a faint, narrow, transient emission line with characteristics reminiscent of the peculiar low-velocity emission features observed in some outbursting dwarf novae. We interpret this feature as a slingshot prominence from the secondary star and derive a maximum source size of 75,000 km and a minimum altitude of 160,000 km above the orbital plane for the prominence. The entropy landscape technique was applied to determine the system parameters of BV Cen. We find M_1 = 1.18 (+0.28 -0.16) Msolar, M_2 = 1.05 (+0.23 -0.14) Msolar and an orbital inclination of i = 53 degrees +- 4 degrees at an optimal systemic velocity of \gamma = -22.3 km s-1. Finally, we also report on the previously unknown binarity of the G5IV star HD 220492.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:06:56 GMT" } ]
2009-11-13T00:00:00
[ [ "Watson", "C. A.", "" ], [ "Steeghs", "D.", "" ], [ "Shahbaz", "T.", "" ], [ "Dhillon", "V. S.", "" ] ]
0707.0740
Richard McClatchey
A. Ali, A. Anjum, J. Bunn, F. Khan, R.McClatchey, H. Newman, C. Steenberg, M. Thomas, Ian Willers
A Multi Interface Grid Discovery System
2 pages, 4 figures. Presented at the Grid 2006 conference, Barcelona Spain
null
null
null
cs.DC
null
Discovery Systems (DS) can be considered as entry points for global loosely coupled distributed systems. An efficient Discovery System in essence increases the performance, reliability and decision making capability of distributed systems. With the rapid increase in scale of distributed applications, existing solutions for discovery systems are fast becoming either obsolete or incapable of handling such complexity. They are particularly ineffective when handling service lifetimes and providing up-to-date information, poor at enabling dynamic service access and they can also impose unwanted restrictions on interfaces to widely available information repositories. In this paper we present essential the design characteristics, an implementation and a performance analysis for a discovery system capable of overcoming these deficiencies in large, globally distributed environments.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:22:45 GMT" } ]
2007-07-06T00:00:00
[ [ "Ali", "A.", "" ], [ "Anjum", "A.", "" ], [ "Bunn", "J.", "" ], [ "Khan", "F.", "" ], [ "McClatchey", "R.", "" ], [ "Newman", "H.", "" ], [ "Steenberg", "C.", "" ], [ "Thomas", "M.", "" ], [ "Willers", "Ian", "" ] ]
0707.0741
Hagai B. Perets
Hagai B. Perets, Yoav Lahini, Francesca Pozzi, Marc Sorel, Roberto Morandotti, Yaron Silberberg
Realization of quantum walks with negligible decoherence in waveguide lattices
4 pages, 3 figures. Added subfigure. Accepted to PRL
Phys. Rev. Lett. 100, 170506 (2008)
10.1103/PhysRevLett.100.170506
null
quant-ph cond-mat.other physics.optics
null
Quantum random walks are the quantum counterpart of classical random walks, and were recently studied in the context of quantum computation. A quantum random walker is subject to self interference, leading to a remarkably different behavior than that of classical random walks such as ballistic propagation or localization due to disorder. Physical implementations of quantum walks have only been made in very small scale systems severely limited by decoherence. Here we show that the propagation of photons in waveguide lattices, which have been studied extensively in recent years, are essentially an implementation of quantum walks. Since waveguide lattices are easily constructed at large scales and display negligible decoherence, they can serve as an ideal and versatile experimental playground for the study of quantum walks and quantum algorithms. We experimentally observe quantum walks in large systems (~100 sites) and confirm quantum walks effects which were studied theoretically, including ballistic propagation, disorder and boundary related effects.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:49:52 GMT" }, { "version": "v2", "created": "Mon, 13 Aug 2007 05:49:47 GMT" }, { "version": "v3", "created": "Wed, 26 Sep 2007 08:34:44 GMT" }, { "version": "v4", "created": "Thu, 10 Apr 2008 11:17:04 GMT" } ]
2008-05-19T00:00:00
[ [ "Perets", "Hagai B.", "" ], [ "Lahini", "Yoav", "" ], [ "Pozzi", "Francesca", "" ], [ "Sorel", "Marc", "" ], [ "Morandotti", "Roberto", "" ], [ "Silberberg", "Yaron", "" ] ]
0707.0742
Richard McClatchey
A. Ali, A. Anjum, T. Azim, J. Bunn, A. Ikram, R. McClatchey, H. Newman, C. Steenberg, M. Thomas, I. Willers
Mobile Computing in Physics Analysis - An Indicator for eScience
8 pages, 7 figures. Presented at the 3rd Int Conf on Mobile Computing & Ubiquitous Networking (ICMU06. London October 2006
null
null
null
cs.DC
null
This paper presents the design and implementation of a Grid-enabled physics analysis environment for handheld and other resource-limited computing devices as one example of the use of mobile devices in eScience. Handheld devices offer great potential because they provide ubiquitous access to data and round-the-clock connectivity over wireless links. Our solution aims to provide users of handheld devices the capability to launch heavy computational tasks on computational and data Grids, monitor the jobs status during execution, and retrieve results after job completion. Users carry their jobs on their handheld devices in the form of executables (and associated libraries). Users can transparently view the status of their jobs and get back their outputs without having to know where they are being executed. In this way, our system is able to act as a high-throughput computing environment where devices ranging from powerful desktop machines to small handhelds can employ the power of the Grid. The results shown in this paper are readily applicable to the wider eScience community.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:32:29 GMT" } ]
2007-07-06T00:00:00
[ [ "Ali", "A.", "" ], [ "Anjum", "A.", "" ], [ "Azim", "T.", "" ], [ "Bunn", "J.", "" ], [ "Ikram", "A.", "" ], [ "McClatchey", "R.", "" ], [ "Newman", "H.", "" ], [ "Steenberg", "C.", "" ], [ "Thomas", "M.", "" ], [ "Willers", "I.", "" ] ]
0707.0743
Richard McClatchey
A. Anjum, R. McClatchey, H. Stockinger, A. Ali, I. Willers, M. Thomas, M. Sagheer, K. Hasham, O. Alvi
DIANA Scheduling Hierarchies for Optimizing Bulk Job Scheduling
8 pages, 9 figures. Presented at the 2nd IEEE Int Conference on eScience & Grid Computing. Amsterdam Netherlands, December 2006
null
10.1109/E-SCIENCE.2006.261173
null
cs.DC
null
The use of meta-schedulers for resource management in large-scale distributed systems often leads to a hierarchy of schedulers. In this paper, we discuss why existing meta-scheduling hierarchies are sometimes not sufficient for Grid systems due to their inability to re-organise jobs already scheduled locally. Such a job re-organisation is required to adapt to evolving loads which are common in heavily used Grid infrastructures. We propose a peer-to-peer scheduling model and evaluate it using case studies and mathematical modelling. We detail the DIANA (Data Intensive and Network Aware) scheduling algorithm and its queue management system for coping with the load distribution and for supporting bulk job scheduling. We demonstrate that such a system is beneficial for dynamic, distributed and self-organizing resource management and can assist in optimizing load or job distribution in complex Grid infrastructures.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:36:18 GMT" } ]
2016-11-17T00:00:00
[ [ "Anjum", "A.", "" ], [ "McClatchey", "R.", "" ], [ "Stockinger", "H.", "" ], [ "Ali", "A.", "" ], [ "Willers", "I.", "" ], [ "Thomas", "M.", "" ], [ "Sagheer", "M.", "" ], [ "Hasham", "K.", "" ], [ "Alvi", "O.", "" ] ]
0707.0744
Inge Bethke
Jan Bergstra, Inge Bethke and Mark Burgess
A process algebra based framework for promise theory
9 pages, 4 figures
null
null
PRG0701
cs.LO
null
We present a process algebra based approach to formalize the interactions of computing devices such as the representation of policies and the resolution of conflicts. As an example we specify how promises may be used in coming to an agreement regarding a simple though practical transportation problem.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:39:14 GMT" } ]
2007-07-06T00:00:00
[ [ "Bergstra", "Jan", "" ], [ "Bethke", "Inge", "" ], [ "Burgess", "Mark", "" ] ]
0707.0745
Richard McClatchey
K. Munir, M. Odeh, R. McClatchey, S. Khan, I. Habib
Semantic Information Retrieval from Distributed Heterogeneous Data Sources
6 pages, 3 figures. Presented at the 4th International Workshop on Frontiers of Information Technology -- FIT 2006. Islamabad, Pakistan December 2006
null
null
null
cs.DB
null
Information retrieval from distributed heterogeneous data sources remains a challenging issue. As the number of data sources increases more intelligent retrieval techniques, focusing on information content and semantics, are required. Currently ontologies are being widely used for managing semantic knowledge, especially in the field of bioinformatics. In this paper we describe an ontology assisted system that allows users to query distributed heterogeneous data sources by hiding details like location, information structure, access pattern and semantic structure of the data. Our goal is to provide an integrated view on biomedical information sources for the Health-e-Child project with the aim to overcome the lack of sufficient semantic-based reformulation techniques for querying distributed data sources. In particular, this paper examines the problem of query reformulation across biomedical data sources, based on merged ontologies and the underlying heterogeneous descriptions of the respective data sources.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:40:19 GMT" } ]
2007-07-06T00:00:00
[ [ "Munir", "K.", "" ], [ "Odeh", "M.", "" ], [ "McClatchey", "R.", "" ], [ "Khan", "S.", "" ], [ "Habib", "I.", "" ] ]
0707.0746
Casey Israel
C. Israel, M. J. Calder\'on and N. D. Mathur
The current spin on manganites
invited review for Materials Today (October 2007 issue), 18 pages, 8 figures
Materials Today 10, 24 (2007)
null
null
cond-mat.mtrl-sci
null
In a material, the existence and coexistence of phases with very different magnetic and electronic properties is both unusual and surprising. Manganites in particular capture the imagination because they demonstrate a complexity that belies their chemically single-phase nature. This complexity arises because the magnetic, electronic and crystal structures interact with one another to deliver exotic magnetic and electronic phases that coexist. This coexistence is self-organized and yet readily susceptible to external perturbations, permitting subtle and imaginative experiments of the type that we describe here. Moreover, these experiments reveal that each competing phase itself remains an incompletely solved mystery.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 09:55:29 GMT" } ]
2008-01-29T00:00:00
[ [ "Israel", "C.", "" ], [ "Calderón", "M. J.", "" ], [ "Mathur", "N. D.", "" ] ]
0707.0747
Stefan Forste
Stefan Forste, Cristina Timirgaziu, Ivonne Zavala
Orientifold's Landscape: Non-Factorisable Six-Tori
24 pages, one figure, v2: references added, v3: small proof added in footnote 5, minor changes, to appear in JHEP
JHEP 0710:025,2007
10.1088/1126-6708/2007/10/025
LTH 748, IPPP/07/37, DCPT/07/74
hep-th hep-ph
null
We construct type IIA orientifolds on T6/(Z2 x Z2) which admit non factorisable lattices. We describe a method to deal with this kind of configurations and discuss how the compactification lattice affects the tadpole cancellation conditions. Moreover, we include D6-branes which are not parallel to O6-planes. These branes can give rise to chiral spectra in four dimensions, thus uncovering a new corner in the landscape of intersecting D-brane model constructions. We demonstrate the construction at an explicit example. In general we argue that obtaining an odd number of families is problematic.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:16:14 GMT" }, { "version": "v2", "created": "Tue, 17 Jul 2007 17:35:43 GMT" }, { "version": "v3", "created": "Thu, 27 Sep 2007 11:18:07 GMT" } ]
2010-02-03T00:00:00
[ [ "Forste", "Stefan", "" ], [ "Timirgaziu", "Cristina", "" ], [ "Zavala", "Ivonne", "" ] ]
0707.0748
Richard McClatchey
F. Estrella, T. Hauer, R. McClatchey, M. Odeh, D Rogulin, T. Solomonides
Experiences of Engineering Grid-Based Medical Software
18 pages, 2 tables, 5 figures. In press International Journal of Medical Informatics. Elsevier publishers
null
null
null
cs.DC
null
Objectives: Grid-based technologies are emerging as potential solutions for managing and collaborating distributed resources in the biomedical domain. Few examples exist, however, of successful implementations of Grid-enabled medical systems and even fewer have been deployed for evaluation in practice. The objective of this paper is to evaluate the use in clinical practice of a Grid-based imaging prototype and to establish directions for engineering future medical Grid developments and their subsequent deployment. Method: The MammoGrid project has deployed a prototype system for clinicians using the Grid as its information infrastructure. To assist in the specification of the system requirements (and for the first time in healthgrid applications), use-case modelling has been carried out in close collaboration with clinicians and radiologists who had no prior experience of this modelling technique. A critical qualitative and, where possible, quantitative analysis of the MammoGrid prototype is presented leading to a set of recommendations from the delivery of the first deployed Grid-based medical imaging application. Results: We report critically on the application of software engineering techniques in the specification and implementation of the MammoGrid project and show that use-case modelling is a suitable vehicle for representing medical requirements and for communicating effectively with the clinical community. This paper also discusses the practical advantages and limitations of applying the Grid to real-life clinical applications and presents the consequent lessons learned.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:06:41 GMT" } ]
2007-07-06T00:00:00
[ [ "Estrella", "F.", "" ], [ "Hauer", "T.", "" ], [ "McClatchey", "R.", "" ], [ "Odeh", "M.", "" ], [ "Rogulin", "D", "" ], [ "Solomonides", "T.", "" ] ]
0707.0749
Efim Zasavitsky
P.G. Globa, E.A.Zasavitsky, V.G.Kantser, S.P.Sidelinikova, A.I.Dikusar
Kinetics of Electrodeposition of Silver and Copper at Template Synthesis of Nanowires
6 pages, 7 figures
null
null
null
cond-mat.mes-hall cond-mat.mtrl-sci
null
The results of investigation of kinetics of nanopores filling into membranes from aluminum oxide (pore diameter - 200 nm, porosity ~ 50%) at electrodeposition of copper and silver are described. It is shown, that at identical quantity of electricity passed through solutions, the degree of pores filling by metal (average thickness of a deposit) is various for copper and silver deposition. Calculated (according Faraday Law) and experimental dependences of deposition rates of these metals on quantity of electricity passed at direct and pulse currents are presented. Galvanodynamic i - v dependences have been obtained at various current scanning rates. The smaller rate of deposition allows to decrease concentration limitations of electrode process and to obtain higher average thickness of metal deposits and higher filling degree. The limiting values of quantity of electricity for direct and pulse currents were determined. The average thickness of silver and copper deposits was obtained. A degree of pores filling, the morphology and chemical microanalysis were studied on cross-section of the membrane, using TESCAN SEM equipped with an Oxford Instruments INCA Enerqy EDX-system.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:08:41 GMT" } ]
2007-07-06T00:00:00
[ [ "Globa", "P. G.", "" ], [ "Zasavitsky", "E. A.", "" ], [ "Kantser", "V. G.", "" ], [ "Sidelinikova", "S. P.", "" ], [ "Dikusar", "A. I.", "" ] ]
0707.0750
Garry Pantelis
Garry Pantelis
Nonlinear PDEs and Scale Dependence
typo corrected
null
null
null
math.AP math.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The properties of nonlinear PDEs that generate filtered solutions are explored with particular attention given to the constraints on the residual term. The analysis is carried out for nonlinear PDEs with an emphasis on evolution problems recast on space-time-scale. We examine the role of approximation that allow for the generation of solutions on isolated scale slices.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:13:44 GMT" }, { "version": "v2", "created": "Thu, 26 Jul 2007 12:40:22 GMT" }, { "version": "v3", "created": "Sat, 24 Apr 2010 17:47:24 GMT" } ]
2010-04-27T00:00:00
[ [ "Pantelis", "Garry", "" ] ]
0707.0751
Federico Corberi
Federico Corberi, Eugenio Lippiello and Marco Zannetti
Fluctuation-Dissipation relations far from Equilibrium
18 pages, 10 figures
J. Stat. Mech. (2007) P07002
10.1088/1742-5468/2007/07/P07002
null
cond-mat.stat-mech
null
In this Article we review some recent progresses in the field of non-equilibrium linear response theory. We show how a generalization of the fluctuation-dissipation theorem can be derived for Markov processes, and discuss the Cugliandolo-Kurchan \cite{Cugliandolo93} fluctuation dissipation relation for aging systems and the theorem by Franz {\it et. al.} \cite{Franz98} relating static and dynamic properties. We than specialize the subject to phase-ordering systems examining the scaling properties of the linear response function and how these are determined by the behavior of topological defects. We discuss how the connection between statics and dynamics can be violated in these systems at the lower critical dimension or as due to stochastic instability.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:16:05 GMT" } ]
2007-07-06T00:00:00
[ [ "Corberi", "Federico", "" ], [ "Lippiello", "Eugenio", "" ], [ "Zannetti", "Marco", "" ] ]
0707.0752
Etienne Gindensperger
Etienne Gindensperger and Lorenz S. Cederbaum
Quantum dynamics in macrosystems with several coupled electronic states: hierarchy of effective Hamiltonians
null
null
10.1063/1.2778682
null
physics.chem-ph
null
We address the nonadiabatic quantum dynamics of macrosystems with several coupled electronic states, taking into account the possibility of multi-state conical intersections. The general situation of an arbitrary number of states and arbitrary number of nuclear degrees of freedom (modes) is considered. The macrosystem is decomposed into a system part carrying a few, strongly coupled modes, and an environment, comprising the vast number of remaining modes. By successively transforming the modes of the environment, a hierarchy of effective Hamiltonians for the environment is constructed. Each effective Hamiltonian depends on a reduced number of effective modes, which carry cumulative effects. By considering the system's Hamiltonian along with a few members of the hierarchy, it is shown mathematically by a moment analysis that the quantum dynamics of the entire macrosystem can be numerically exactly computed on a given time-scale. The time scale wanted defines the number of effective Hamiltonians to be included. The contribution of the environment to the quantum dynamics of the macrosystem translates into a sequential coupling of effective modes. The wavefunction of the macrosystem is known in the full space of modes, allowing for the evaluation of observables such as the time-dependent individual excitation along modes of interest, as well a spectra and electronic-population dynamics.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:19:16 GMT" } ]
2009-11-13T00:00:00
[ [ "Gindensperger", "Etienne", "" ], [ "Cederbaum", "Lorenz S.", "" ] ]
0707.0753
A. L. Kuzemsky
A. L. Kuzemsky
Theory of Transport Processes and the Method of the Nonequilibrium Statistical Operator
This submission has been removed by arXiv admin because the files submitted were incomplete
Intern. J. Modern Phys. B21, Issue 17 (10 July) (2007), pp.1-129
10.1142/S0217979207037417
null
cond-mat.stat-mech
null
The aim of this review is to provide better understanding of a few approaches that have been proposed for treating nonequilibrium (time-dependent) processes in statistical mechanics with the emphasis on the inter-relation between theories. The ensemble method, as it was formulated by J. W. Gibbs, have the great generality and the broad applicability to equilibrium statistical mechanics. Different macroscopic environmental constraints lead to different types of ensembles, with particular statistical characteristics. In the present work, the statistical theory of nonequilibrium processes which is based on nonequilibrium ensemble formalism is discussed. The kinetic approach to dynamic many-body problems, which is important from the point of view of the fundamental theory of irreversibility, is alluded to. The emphasis is on the method of the nonequilibrium statistical operator (NSO) developed by D. N. Zubarev. The NSO method permits one to generalize the Gibbs ensemble method to the nonequilibrium case and to construct a nonequilibrium statistical operator which enables one to obtain the transport equations and calculate the transport coefficients in terms of correlation functions, and which, in the case of equilibrium, goes over to the Gibbs distribution. Although some space is devoted to the formal structure of the NSO method, the emphasis is on its utility. Applications to specific problems such as the generalized transport and kinetic equations, and a few examples of the relaxation and dissipative processes, which manifest the operational ability of the method, are considered.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:20:27 GMT" } ]
2009-11-13T00:00:00
[ [ "Kuzemsky", "A. L.", "" ] ]
0707.0754
Denis Semenov A.
Denis A. Semenov
The Symmetry of the Genetic Code and a Universal Trend of Amino Acid Gain and Loss
7 pages, 3 tables
null
null
null
q-bio.PE
null
Part 1 of the study intends to show that the universal trend of amino acid gain and loss discovered by Jordan et al. (2005) can be accounted for by the spontaneity of DNA typical damages. These damages lead to replacements of guanine and cytosine by thymine. Part 2 proposes a hypothesis of the evolution of the genetic code, the leading mechanism of which is the nucleotide spontaneous damage. The hypothesis accounts for the universal trend of amino acid gain and loss, stability of the genetic code towards point mutations, the presence of code dialects, and the symmetry of the genetic code table.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:29:00 GMT" } ]
2007-07-06T00:00:00
[ [ "Semenov", "Denis A.", "" ] ]
0707.0755
Zahera Jabeen
Zahera Jabeen (IITM) and Neelima Gupte (IITM)
A cellular automaton identification of the universality classes of spatiotemporal intermittency
11 pages, 6 figures
null
null
null
nlin.CD
null
The phase diagram of the coupled sine circle map lattice shows spatio-temporal intermittency of two distinct types: spatio-temporal intermittency of the directed percolation (DP) class, and spatial intermittency which does not belong to this class. These two types of behaviour are seen to be special cases of the spreading and non-spreading regimes seen in the system. In the spreading regime, each site can infect its neighbours permitting an initial disturbance to spread, whereas in the non-spreading regime no infection is possible. The two regimes are separated by a line which we call the infection line. The coupled map lattice can be mapped on to an equivalent cellular automaton which shows a transition from a probabilistic cellular automaton (PCA) to a deterministic cellular automaton (DCA) at the infection line. Thus the existence of the DP and non-DP universality classes in the same system is signalled by the PCA to DCA transition. We also discuss the dynamic origin of this transition.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:35:28 GMT" } ]
2007-07-06T00:00:00
[ [ "Jabeen", "Zahera", "", "IITM" ], [ "Gupte", "Neelima", "", "IITM" ] ]
0707.0756
Naomichi Hatano
Ernesto Estrada and Naomichi Hatano
Communicability in complex networks
20 pages, 5 figures
Phys. Rev. E 77, 036111 (2008)
10.1103/PhysRevE.77.036111
null
physics.soc-ph cond-mat.stat-mech
null
Many topological and dynamical properties of complex networks are defined by assuming that most of the transport on the network flows along the shortest paths. However, there are different scenarios in which non-shortest paths are used to reach the network destination. Thus the consideration of the shortest paths only does not account for the global communicability of a complex network. Here we propose a new measure of the communicability of a complex network, which is a broad generalization of the concept of the shortest path. According to the new measure, most of real-world networks display the largest communicability between the most connected (popular) nodes of the network (assortative communicability). There are also several networks with the disassortative communicability, where the most "popular" nodes communicate very poorly to each other. Using this information we classify a diverse set of real-world complex systems into a small number of universality classes based on their structure-dynamic correlation. In addition, the new communicability measure is able to distinguish finer structures of networks, such as communities into which a network is divided. A community is unambiguously defined here as a set of nodes displaying larger communicability among them than to the rest of nodes in the network.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:40:05 GMT" } ]
2008-12-16T00:00:00
[ [ "Estrada", "Ernesto", "" ], [ "Hatano", "Naomichi", "" ] ]
0707.0757
Thomas Krajewski
J.-H. Jureit, T. Krajewski
Quasi-quantum groups from strings
10 pages, 8 figures, talk given at the conference "Noncommutative Geometry and Physics", Orsay April 2007
J.Phys.Conf.Ser.103:012005,2008
10.1088/1742-6596/103/1/012005
CPT-P31-2007
hep-th
null
Motivated by string theory on the orbifold ${\cal M}/G$ in presence of a Kalb-Ramond field strength $H$, we define the operators that lift the group action to the twisted sectors. These operators turn out to generate the quasi-quantum group $D_{\omega}[G]$, introduced in the context of conformal field theory by R. Dijkgraaf, V. Pasquier and P. Roche, with $\omega$ a 3-cocycle determined by a series of cohomological equations in a tricomplex combining de Rham, \u{C}ech and group cohomologies. We further illustrate some properties of the quasi-quantum group from a string theoretical point of view.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:52:44 GMT" } ]
2008-11-26T00:00:00
[ [ "Jureit", "J. -H.", "" ], [ "Krajewski", "T.", "" ] ]
0707.0758
Ram\'on Oliver
M. Luna, J. Terradas, R. Oliver, J.L. Ballester
Transverse oscillations of two coronal loops
Accepted for publication in The Astrophysical Journal
null
10.1086/528367
null
astro-ph
null
We study transverse fast magnetohydrodynamic waves in a system of two coronal loops modeled as smoothed, dense plasma cylinders in a uniform magnetic field. The collective oscillatory properties of the system due to the interaction between the individual loops are investigated from two points of view. Firstly, the frequency and spatial structure of the normal modes are studied. The system supports four trapped normal modes in which the loops move rigidly in the transverse direction. The direction of the motions is either parallel or perpendicular to the plane containing the axes of the loops. Two of these modes correspond to oscillations of the loops in phase, while in the other two they move in antiphase. Thus, these solutions are the generalization of the kink mode of a single cylinder to the double cylinder case. Secondly, we analyze the time-dependent problem of the excitation of the pair of tubes. We find that depending on the shape and location of the initial disturbance, different normal modes can be excited. The frequencies of normal modes are accurately recovered from the numerical simulations. In some cases, because of the simultaneous excitation of several eigenmodes, the system shows beating and the phase lag between the loops is $\pi/2$.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 10:57:58 GMT" }, { "version": "v2", "created": "Tue, 11 Dec 2007 11:15:15 GMT" } ]
2009-11-13T00:00:00
[ [ "Luna", "M.", "" ], [ "Terradas", "J.", "" ], [ "Oliver", "R.", "" ], [ "Ballester", "J. L.", "" ] ]
0707.0759
Andrzej Grudka
Andrzej Grudka and Joanna Modlawska
Optimal state in the Knill-Laflamme-Milburn scheme of linear optical teleportation
4 pages
Phys. Rev. A 77, 014301 (2008)
10.1103/PhysRevA.77.014301
null
quant-ph
null
We discuss some properties of the Knill-Laflamme-Milburn scheme for quantum teleportation with both maximally and nonmaximally entangled states. We derive the error correction scheme when one performs teleportation with nonmaximally entangled states and we find the probability for perfect teleportation. We show that the maximally entangled state is optimal in such a case. We also show how the error correction scheme can be implemented experimentally when one uses polarization encoding.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:02:31 GMT" }, { "version": "v2", "created": "Sat, 15 Dec 2007 18:20:32 GMT" } ]
2008-07-24T00:00:00
[ [ "Grudka", "Andrzej", "" ], [ "Modlawska", "Joanna", "" ] ]
0707.0760
Javier Negro
P. G. Estevez, S. Kuru, J. Negro and L. M. Nieto
Travelling wave solutions of the generalized Benjamin-Bona-Mahony equation
19 pages. To appear in CS&F
null
null
null
nlin.SI
null
A class of particular travelling wave solutions of the generalized Benjamin-Bona-Mahony equation is studied systematically using the factorization technique. Then, the general travelling wave solutions of Benjamin-Bona-Mahony equation, and of its modified version, are also recovered.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:30:29 GMT" }, { "version": "v2", "created": "Mon, 17 Sep 2007 15:09:08 GMT" } ]
2007-09-17T00:00:00
[ [ "Estevez", "P. G.", "" ], [ "Kuru", "S.", "" ], [ "Negro", "J.", "" ], [ "Nieto", "L. M.", "" ] ]
0707.0761
Richard McClatchey
David Manset, Herve Verjus, Richard McClatchey
Managing Separation of Concerns in Grid Applications Through Architectural Model Transformations
4 pages, 2 figures. Presented at the First European Conference on Software Architectures (ECSA 2007). Madrid, Spain September 24-26, 2007
null
null
null
cs.SE cs.DC
null
Grids enable the aggregation, virtualization and sharing of massive heterogeneous and geographically dispersed resources, using files, applications and storage devices, to solve computation and data intensive problems, across institutions and countries via temporary collaborations called virtual organizations (VO). Most implementations result in complex superposition of software layers, often delivering low quality of service and quality of applications. As a consequence, Grid-based applications design and development is increasingly complex, and the use of most classical engineering practices is unsuccessful. Not only is the development of such applications a time-consuming, error prone and expensive task, but also the resulting applications are often hard-coded for specific Grid configurations, platforms and infra-structures. Having neither guidelines nor rules in the design of a Grid-based application is a paradox since there are many existing architectural approaches for distributed computing, which could ease and promote rigorous engineering methods based on the re-use of software components. It is our belief that ad-hoc and semi-formal engineer-ing approaches, in current use, are insufficient to tackle tomorrows Grid develop-ments requirements. Because Grid-based applications address multi-disciplinary and complex domains (health, military, scientific computation), their engineering requires rigor and control. This paper therefore advocates a formal model-driven engineering process and corresponding design framework and tools for building the next generation of Grids.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:10:03 GMT" } ]
2007-07-06T00:00:00
[ [ "Manset", "David", "" ], [ "Verjus", "Herve", "" ], [ "McClatchey", "Richard", "" ] ]
0707.0762
Richard McClatchey
Irfan Habib, Kamran Soomro, Ashiq Anjum, Richard McClatchey, Arshad Ali, Peter Bloodsworth
PhantomOS: A Next Generation Grid Operating System
8 pages, 6 figures. Presented at the UK eScience All Hands Meeting 2007 (AHM07). Nottingham, UK. September 2007
null
null
null
cs.DC
null
Grid Computing has made substantial advances in the past decade; these are primarily due to the adoption of standardized Grid middleware. However Grid computing has not yet become pervasive because of some barriers that we believe have been caused by the adoption of middleware centric approaches. These barriers include: scant support for major types of applications such as interactive applications; lack of flexible, autonomic and scalable Grid architectures; lack of plug-and-play Grid computing and, most importantly, no straightforward way to setup and administer Grids. PhantomOS is a project which aims to address many of these barriers. Its goal is the creation of a user friendly pervasive Grid computing platform that facilitates the rapid deployment and easy maintenance of Grids whilst providing support for major types of applications on Grids of almost any topology. In this paper we present the detailed system architecture and an overview of its implementation.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:14:45 GMT" } ]
2007-07-06T00:00:00
[ [ "Habib", "Irfan", "" ], [ "Soomro", "Kamran", "" ], [ "Anjum", "Ashiq", "" ], [ "McClatchey", "Richard", "" ], [ "Ali", "Arshad", "" ], [ "Bloodsworth", "Peter", "" ] ]
0707.0763
Richard McClatchey
Ashiq Anjum, Peter Bloodsworth, Andrew Branson, Tamas Hauer, Richard McClatchey, Kamran Munir, Dmitry Rogulin, Jetendr Shamdasani
The Requirements for Ontologies in Medical Data Integration: A Case Study
6 pages, 1 figure. Presented at the 11th International Database Engineering & Applications Symposium (Ideas2007). Banff, Canada September 2007
null
null
null
cs.DB
null
Evidence-based medicine is critically dependent on three sources of information: a medical knowledge base, the patients medical record and knowledge of available resources, including where appropriate, clinical protocols. Patient data is often scattered in a variety of databases and may, in a distributed model, be held across several disparate repositories. Consequently addressing the needs of an evidence-based medicine community presents issues of biomedical data integration, clinical interpretation and knowledge management. This paper outlines how the Health-e-Child project has approached the challenge of requirements specification for (bio-) medical data integration, from the level of cellular data, through disease to that of patient and population. The approach is illuminated through the requirements elicitation and analysis of Juvenile Idiopathic Arthritis (JIA), one of three diseases being studied in the EC-funded Health-e-Child project.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:21:39 GMT" } ]
2007-07-06T00:00:00
[ [ "Anjum", "Ashiq", "" ], [ "Bloodsworth", "Peter", "" ], [ "Branson", "Andrew", "" ], [ "Hauer", "Tamas", "" ], [ "McClatchey", "Richard", "" ], [ "Munir", "Kamran", "" ], [ "Rogulin", "Dmitry", "" ], [ "Shamdasani", "Jetendr", "" ] ]
0707.0764
Branko Dragovich
Branko Dragovich and Alexandra Dragovich
p-Adic Degeneracy of the Genetic Code
11 pages, 1 table. Published in the Proceedings of '4th Summer School in Modern Mathematcal Physics', September 2006, Belgrade (Serbia)
SFIN XX A1 (2007) 179-188
null
null
q-bio.GN cs.IT math.IT physics.bio-ph
null
Degeneracy of the genetic code is a biological way to minimize effects of the undesirable mutation changes. Degeneration has a natural description on the 5-adic space of 64 codons $\mathcal{C}_5 (64) = \{n_0 + n_1 5 + n_2 5^2 : n_i = 1, 2, 3, 4 \} ,$ where $n_i$ are digits related to nucleotides as follows: C = 1, A = 2, T = U = 3, G = 4. The smallest 5-adic distance between codons joins them into 16 quadruplets, which under 2-adic distance decay into 32 doublets. p-Adically close codons are assigned to one of 20 amino acids, which are building blocks of proteins, or code termination of protein synthesis. We shown that genetic code multiplets are made of the p-adic nearest codons.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:40:53 GMT" } ]
2007-07-16T00:00:00
[ [ "Dragovich", "Branko", "" ], [ "Dragovich", "Alexandra", "" ] ]
0707.0765
Ugo Tartaglino
Xiao-Hua Zhang, Ugo Tartaglino, Giuseppe E. Santoro, Erio Tosatti
Velocity plateaus and jumps in carbon nanotube sliding
9 pages, 5 color figures, format latex Elsart. Surface Science, in press, http://dx.doi.org/10.1016/j.susc.2007.05.034
Surface Science 601, 3693-3696 (2007)
10.1016/j.susc.2007.05.034
null
cond-mat.mtrl-sci
null
The friction between concentric carbon nanotubes sliding one inside the other has been widely studied and simulated, but not so far using external force as the driving variable. Our molecular dynamics (MD) simulations show that as the pulling force grows, the sliding velocity increases by jumps and plateaus rather than continuously as expected. Dramatic friction peaks (similar to that recently noted by Tangney {\it et al.} in Phys. Rev. Lett. 97 (2006) 195901) which develop around some preferential sliding velocities, are at the origin of this phenomenon. The (stable) rising edge of the peak produces a velocity plateau; the (unstable) dropping edge produces a jump to the nearest stable branch. The outcome is reminiscent of conduction in ionized gases, the plateau correspon ding to a current stabilization against voltage variations, the jump corresponding to a discharge or breakdown.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:42:17 GMT" } ]
2011-11-10T00:00:00
[ [ "Zhang", "Xiao-Hua", "" ], [ "Tartaglino", "Ugo", "" ], [ "Santoro", "Giuseppe E.", "" ], [ "Tosatti", "Erio", "" ] ]
0707.0766
Leo Stodolsky
I. Bavykina, P.Christ, P.Huff, J.Ninkovic, F.Proebst, W.Seidel, and L. Stodolsky
Interpretation of Light-Quenching Factor Measurements
Seven pages, seven figures, some with color
Astropart.Phys.28:489-493,2007
10.1016/j.astropartphys.2007.09.006
null
physics.ins-det
null
We observe that the pattern of the quenching factors for scintillation light from various ions, recently studied in $CaWO_4$ in connection with dark matter detectors, can be understood as a saturation phenomenon in which the light output is simply proportional to track length, independent of the ion and its energy. This observation is in accord with the high dE/dx limit of Birks' law. It suggests a simple model for the intrinsic resolution of light detectors for low energy ions, which we briefly discuss.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 11:54:49 GMT" } ]
2009-06-23T00:00:00
[ [ "Bavykina", "I.", "" ], [ "Christ", "P.", "" ], [ "Huff", "P.", "" ], [ "Ninkovic", "J.", "" ], [ "Proebst", "F.", "" ], [ "Seidel", "W.", "" ], [ "Stodolsky", "L.", "" ] ]
0707.0767
Nicolas Michel
N. Michel, W. Nazarewicz and M. Ploszajczak
Continuum Coupling and Single-Nucleon Overlap Integrals
9 figures; 23 pages; corrected version; accepted in Nuclear Physics A
Nucl.Phys.A794:29-46,2007
10.1016/j.nuclphysa.2007.07.004
null
nucl-th
null
The presence of a particle continuum, both of a resonant and non-resonant character, can significantly impact spectroscopic properties of weakly bound nuclei and excited nuclear states close to, and above, the particle emission threshold. In the framework of the continuum shell model in the complex momentum-plane, the so-called Gamow Shell Model, we discuss salient effects of the continuum coupling on the one-neutron overlap integrals and the associated spectroscopic factors in neutron-rich helium and oxygen nuclei. In particular, we demonstrate a characteristic near-threshold energy dependence of the spectroscopic factors for different l-waves. We show also that the realistic radial overlap functions, which are needed for the description of transfer reactions, can be generated by single-particle wave functions of the appropriately chosen complex potential.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:12:03 GMT" }, { "version": "v2", "created": "Mon, 23 Jul 2007 12:14:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Michel", "N.", "" ], [ "Nazarewicz", "W.", "" ], [ "Ploszajczak", "M.", "" ] ]
0707.0768
W. Prellier
P. Padhan, W. Prellier and R.C. Budhani
Anomalous exchange coupling in transition-metal-oxide based superlattices with antiferromagnetic spacer layers
Submitted to J. Appl. Phys
J. Appl. Phys. 102 (2007) 043909
10.1063/1.2770818
null
cond-mat.str-el cond-mat.mtrl-sci
null
A direct correlation is seen between the coercive field (HC) and the magnetic-field-dependent resistivity (MR) in SrMnO3/SrRuO3 superlattices of perpendicular magnetic anisotropy. The magnetoresistance shows a sharp jump at Hc for in-plane current and the out-of-plane magnetic field. Both HC and high-field MR also oscillate with the thickness of the SrMnO3 spacer layers separating the metallic ruthenate. Since the spacer in these superlattices has no mobile carriers to facilitate an oscillatory coupling, we attribute the observed behavior to the spin-polarized quantum tunneling of electrons between the ferromagnetic layers and antiferromagnetically ordered t2g spins of SrMnO3.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:17:34 GMT" } ]
2009-11-13T00:00:00
[ [ "Padhan", "P.", "" ], [ "Prellier", "W.", "" ], [ "Budhani", "R. C.", "" ] ]
0707.0769
Makoto Umeki Dr.
Makoto Umeki
Double Periodicity and Frequency-Locking in the Langford Equation
9 pages, 10 figures, 2 tables, submitted to JJIAM
null
null
null
physics.flu-dyn physics.gen-ph
null
The bifurcation structure of the Langford equation is studied numerically in detail. Periodic, doubly-periodic, and chaotic solutions and the routes to chaos via coexistence of double periodicity and period-doubling bifurcations are found by the Poincar\'e plot of successive maxima of the first mode $x_1$. Frequency-locked periodic solutions corresponding to the Farey sequence $F_n$ are examined up to $n=14$. Period-doubling bifurcations appears on some of the periodic solutions and the similarity of bifurcation structures between the sine-circle map and the Langford equation is shown. A method to construct the Poincar\'e section for triple periodicity is proposed.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:53:48 GMT" } ]
2007-07-06T00:00:00
[ [ "Umeki", "Makoto", "" ] ]
0707.0770
Ardiley Torres Avelar
Simone Souza, A. T. Avelar, J. M. C. Malbouisson, and B. Baseia
Conditional displacement operator for traveling fields
null
null
10.1016/j.optcom.2008.01.056
null
quant-ph
null
We show that the conditional displacement operator $\hat{U}_{CD}=\exp [\hat{b}^{\dagger}\hat{b}(\beta \hat{a}^{\dagger}-\beta ^{\ast}\hat{a})]$ acting upon an arbitrary state of traveling waves can be well approximated by the action of a Kerr medium placed between two beam splitters whose respective second ports are fed by highly excited coherent states. Applications to the generation of nonclassical states and measurement of Wigner function of arbitrary states are also considered.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:39:48 GMT" } ]
2009-11-13T00:00:00
[ [ "Souza", "Simone", "" ], [ "Avelar", "A. T.", "" ], [ "Malbouisson", "J. M. C.", "" ], [ "Baseia", "B.", "" ] ]
0707.0771
Sergey Ivashkovich
S. Ivashkovich, V. Shevchishin
Local properties of J-complex curves in Lipschitz-continuous structures
Minor corrections and improvements. One example added. To appear in Math. Zeitschrift.
null
null
null
math.CV math.SG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We prove the existence of primitive curves and positivity of intersections of $J$-complex curves for Lipschitz-continuous almost complex structures. These results are deduced from the Comparison Theorem for $J$-holomorphic maps in Lipschitz structures, previously known for $J$ of class $C^{1, Lip}$. We also give the optimal regularity of curves in Lipschitz structures. It occurs to be $C^{1,LnLip}$, i.e. the first derivatives of a $J$-complex curve for Lipschitz $J$ are Log-Lipschitz-continuous. A simple example that nothing better can be achieved is given. Further we prove the Genus Formula for $J$-complex curves and determine their principal Puisieux exponents (all this for Lipschitz-continuous $J$-s).
[ { "version": "v1", "created": "Thu, 5 Jul 2007 12:41:08 GMT" }, { "version": "v2", "created": "Sat, 14 Mar 2009 12:38:27 GMT" }, { "version": "v3", "created": "Tue, 13 Oct 2009 08:48:28 GMT" }, { "version": "v4", "created": "Thu, 1 Apr 2010 13:07:38 GMT" } ]
2015-03-13T00:00:00
[ [ "Ivashkovich", "S.", "" ], [ "Shevchishin", "V.", "" ] ]
0707.0772
Xavier-Fran\c{c}ois Roblot
Christophe Delaunay and Xavier-Fran\c{c}ois Roblot
Regulators of rank one quadratic twists
28 pages with 32 figures
null
null
null
math.NT
null
We investigate the regulators of elliptic curves with rank 1 in some families of quadratic twists of a fixed elliptic curve. In particular, we formulate some conjectures on the average size of these regulators. We also describe an efficient algorithm to compute explicitly some of the invariants of an odd quadratic twist of an elliptic curve (regulator, order of the Tate-Shafarevich group, etc.) and we discuss the numerical data that we obtain and compare it with our predictions.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:02:50 GMT" }, { "version": "v2", "created": "Wed, 6 Feb 2008 16:18:00 GMT" } ]
2008-02-06T00:00:00
[ [ "Delaunay", "Christophe", "" ], [ "Roblot", "Xavier-François", "" ] ]
0707.0773
Christian Schwinn
Martin Beneke, Pietro Falgari, Christian Schwinn (RWTH Aachen), Adrian Signer (IPPP Durham), Giulia Zanderighi (CERN)
Four-fermion production near the W pair production threshold
53 pages, v2: version to be published, inessential modifications
Nucl.Phys.B792:89-135,2008
10.1016/j.nuclphysb.2007.09.030
PITHA 07/05, IPPP/07/35, CERN-PH-TH-07-107
hep-ph hep-ex
null
We perform a dedicated study of the four-fermion production process e- e+ -> mu- nubar_mu u dbar X near the W pair-production threshold in view of the importance of this process for a precise measurement of the W boson mass. Accurate theoretical predictions for this process require a systematic treatment of finite-width effects. We use unstable-particle effective field theory (EFT) to perform an expansion in the coupling constants, GammaW/MW, and the non-relativistic velocity v of the W boson up to next-to-leading order in GammaW/MW ~ alpha_ew ~ v^2. We find that the dominant theoretical uncertainty in MW is currently due to an incomplete treatment of initial-state radiation. The remaining uncertainty of the NLO EFT calculation translates into delta MW ~ 10-15 MeV, and to about 5 MeV with additional input from the NLO four-fermion calculation in the full theory.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:51:31 GMT" }, { "version": "v2", "created": "Tue, 23 Oct 2007 09:46:12 GMT" } ]
2008-11-26T00:00:00
[ [ "Beneke", "Martin", "", "RWTH Aachen" ], [ "Falgari", "Pietro", "", "RWTH Aachen" ], [ "Schwinn", "Christian", "", "RWTH Aachen" ], [ "Signer", "Adrian", "", "IPPP Durham" ], [ "Zanderighi", "Giulia", "", "CERN" ] ]
0707.0774
Daniel Alpay A
Daniel Alpay, Olga Timoshenko, and Dan Volok
Caratheodory-Fejer interpolation and related topics in locally convex spaces
null
null
null
null
math.FA math.CV
null
We study Caratheodory-Herglotz functions whose values are continuous operators from a locally convex topological space which admits the factorization property into its conjugate dual space. We show how this case can be reduced to the case of functions whose values are bounded operators from a Hilbert space into itself.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:04:36 GMT" } ]
2007-07-06T00:00:00
[ [ "Alpay", "Daniel", "" ], [ "Timoshenko", "Olga", "" ], [ "Volok", "Dan", "" ] ]
0707.0775
Falk Bruckmann
Falk Bruckmann
Instanton constituents in the O(3) model at finite temperature
5 pages, 12 plots in 3 figures
Phys.Rev.Lett.100:051602,2008
10.1103/PhysRevLett.100.051602
null
hep-th cond-mat.str-el hep-lat hep-ph
null
It is shown that instantons in the O(3) model at finite temperature consist of fractional charge constituents and the (topological) properties of the latter are discussed.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:15:45 GMT" } ]
2008-11-26T00:00:00
[ [ "Bruckmann", "Falk", "" ] ]
0707.0776
Eitan Rowen
E. E. Rowen, N. Bar-Gill, R. Pugatch, N. Davidson
Damping of bulk excitations over an elongated BEC - the role of radial modes
5 pages, 4 figures
null
10.1103/PhysRevA.77.033602
null
cond-mat.other
null
We report the measurement of Beliaev damping of bulk excitations in cigar shaped Bose Einstein condensates of atomic vapor. By using post selection, excitation line shapes of the total population are compared with those of the undamped excitations. We find that the damping depends on the initial excitation energy of the decaying quasi particle, as well as on the excitation momentum. We model the condensate as an infinite cylinder and calculate the damping rates of the different radial modes. The derived damping rates are in good agreement with the experimentally measured ones. The damping rates strongly depend on the destructive interference between pathways for damping, due to the quantum many-body nature of both excitation and damping products.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:19:11 GMT" } ]
2013-05-29T00:00:00
[ [ "Rowen", "E. E.", "" ], [ "Bar-Gill", "N.", "" ], [ "Pugatch", "R.", "" ], [ "Davidson", "N.", "" ] ]
0707.0777
Christophe Adami
C. Adami, M.P. Ulmer, F. Durret, G. Covone, E. Cypriano, et al
An extension of the SHARC survey
Accepted in A&A
null
10.1051/0004-6361:20077243
null
astro-ph
null
We report on our search for distant clusters of galaxies based on optical and X-ray follow up observations of X-ray candidates from the SHARC survey. Based on the assumption that the absence of bright optical or radio counterparts to possibly extended X-ray sources could be distant clusters. We have obtained deep optical images and redshifts for several of these objects and analyzed archive XMM-Newton or Chandra data where applicable. In our list of candidate clusters, two are probably galaxy structures at redshifts of z$\sim$0.51 and 0.28. Seven other structures are possibly galaxy clusters between z$\sim$0.3 and 1. Three sources are identified with QSOs and are thus likely to be X-ray point sources, and six more also probably fall in this category. One X-ray source is spurious or variable. For 17 other sources, the data are too sparse at this time to put forward any hypothesis on their nature. We also serendipitously detected a cluster at z=0.53 and another galaxy concentration which is probably a structure with a redshift in the [0.15-0.6] range. We discuss these results within the context of future space missions to demonstrate the necessity of a wide field of view telescope optimized for the 0.5-2 keV range.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:13:27 GMT" } ]
2009-11-13T00:00:00
[ [ "Adami", "C.", "" ], [ "Ulmer", "M. P.", "" ], [ "Durret", "F.", "" ], [ "Covone", "G.", "" ], [ "Cypriano", "E.", "" ] ]
0707.0778
Manuel Gadella
M. Gadella, S. Wickramasekara
On the applications of Hardy class functions in scattering theory
22 pages
null
null
null
math-ph math.MP
null
This paper is a response to an article (R. de la Madrid, Journal of Physics A: Mathematical and General, 39,9255-9268 (2006)) recently published in Journal of Physics A: Mathematical and Theoretical. The article claims that the theory of resonances and decaying states based on certain rigged Hilbert spaces of Hardy functions is physically untenable. In this paper we show that all of the key conclusions of the cited article are the result of either the errors in mathematical reasoning or an inadequate understanding of the literature on the subject.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:30:37 GMT" } ]
2007-07-06T00:00:00
[ [ "Gadella", "M.", "" ], [ "Wickramasekara", "S.", "" ] ]
0707.0779
Mustapha Rais
Mustapha Ra\"is
Note sur les invariants du groupe affine
null
null
null
null
math.RT
null
In the paper, it is proved that any $C^{1}$-function on GL(n) which is locally $P$-invariant (here $P$ is the affine (sub)group of GL(n)) is locally $G$-invairant. There is also a statement for distributions (a very weak form of Baruch's results).
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:39:02 GMT" } ]
2007-07-06T00:00:00
[ [ "Raïs", "Mustapha", "" ] ]
0707.0780
Boris Zilber
B.Zilber
Non-commutative Zariski geometries and their classical limit
null
null
null
null
math.QA math.LO
null
We undertake a case study of two series of nonclassical Zariski geometries. We show that these geometries can be realised as representations of certain noncommutative $C^*$-algebras and introduce a natural limit construction which for each of the two series produces a classical U(1)-gauge field over a 2-dimensional Riemann surface.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:39:31 GMT" } ]
2007-07-06T00:00:00
[ [ "Zilber", "B.", "" ] ]
0707.0781
Evgeny Komarov
E.V.Komarov, Yu.A.Simonov
Nonperturbative equation of state of quark-gluon plasma. Applications
20 pages, 6 figures
AnnalsPhys.323:783-811,2008; AnnalsPhys.323:1230-1246,2008
10.1016/j.aop.2007.05.007 10.1016/j.aop.2007.07.005
null
hep-ph
null
The vacuum-driven nonperturbative factors $L_i$ for quark and gluon Green's functions are shown to define the nonperturbative dynamics of QGP in the leading approximation. EoS obtained recently in the framework of this approach is compared in detail with known lattice data for $\mu=0$ including $P/T^4$, $\epsilon/T^4$, $\frac{\epsilon-3P}{T^4}$. The basic role in the dynamics at $T\la 3T_c$ is played by the factors $L_i$ which are approximately equal to the modulus of Polyakov line for quark $L_{fund}$ and gluon $L_{adj}$. The properties of $L_i$ are derived from field correlators and compared to lattice data, in particular the Casimir scaling property $L_{adj} =(L_{fund})^{\frac{C_2(adj)}{C_2(fund)}}$ follows in the Gaussian approximation valid for small vacuum correlation lengths. Resulting curves for $P/T^4$, $\epsilon/T^4$, $\frac{\epsilon-3P}{T^4}$ are in a reasonable agreement with lattice data, the remaining difference points out to an effective attraction among QGP constituents.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:57:09 GMT" }, { "version": "v2", "created": "Tue, 25 Sep 2007 14:17:28 GMT" } ]
2008-11-26T00:00:00
[ [ "Komarov", "E. V.", "" ], [ "Simonov", "Yu. A.", "" ] ]
0707.0782
Mustapha Rais
Mustapha Ra\"is
Notes sur la notion d'invariant caract\'eristique
null
null
null
null
math.RT
null
Let $G$ be a Lie group acting on a vector space $V$. Given a set of $G$-invariants, one can ask the question : does this set of invariants characterize the group $G$ ? We recall here some known results, ask questions and state some conjectures for different choices of invariants : polynomial functions, orbits, distributions, and different types of groups.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:43:32 GMT" } ]
2007-07-06T00:00:00
[ [ "Raïs", "Mustapha", "" ] ]
0707.0783
Marian Aprodu
Marian Aprodu (IMAR) and Daniel Naie (LAREMA)
Log-canonical threshold for curves on a smooth surface
null
null
null
null
math.AG
null
It is shown that the log-canonical threshold of a curve with an isolated singularity is computed by the term ideal of the curve in a suitable system of local parameters at the singularity. The proof uses the Enriques diagram of the singularity and shows that the log-canonical threshold depends only on a non-degenerate path of that diagram.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:48:38 GMT" } ]
2007-07-06T00:00:00
[ [ "Aprodu", "Marian", "", "IMAR" ], [ "Naie", "Daniel", "", "LAREMA" ] ]
0707.0784
Miguel Araujo
M.A.N Araujo, J. Berakdar, V.K. Dugaev and V. R. Vieira
Role of a spin-flip scatterer in a magnetized Luttinger liquid
6 pages, 2 figures
Phys. Rev. B76, 205107 (2007)
10.1103/PhysRevB.76.205107
null
cond-mat.str-el
null
We study the spin-dependent scattering of charge carriers in a magnetized one dimensional Luttinger liquid from a localized non-homogeneous magnetic field, which might be brought about by the stray field of magnetic tip near a uniform liquid, or by a transverse domain wall (DW) between two oppositely magnetized liquids. From a renormalization group treatment of the electron interactions we deduce scaling equations for the transmission and reflection amplitudes as the bandwidth is progressively reduced to an energy scale set by the temperature. The repulsive interactions dictate two possible zero temperature insulator fixed points: one in which electrons are reflected in the same spin channel and another where the electron spin is reversed upon reflection. In the latter case, a finite spin current emerges in the absence of a charge current at zero temperature and the Friedel oscillations form a transverse spiraling spin density. Adding a purely potential scattering term has no effect on the fixed points of a uniformly magnetized liquid. For a DW we find that the introduction of potential scattering stabilizes the spin-flip insulator phase even if the single-particle spin-flip scattering produced by the DW is arbitrarily weak. The potential can be induced externally, e.g. by a local gate voltage or a constriction, providing a means for controlling the transport properties of the wire.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:53:13 GMT" } ]
2013-02-15T00:00:00
[ [ "Araujo", "M. A. N", "" ], [ "Berakdar", "J.", "" ], [ "Dugaev", "V. K.", "" ], [ "Vieira", "V. R.", "" ] ]
0707.0785
Matthieu Picantin
Matthieu Picantin (LIAFA)
Garside monoids vs divisibility monoids
null
null
null
null
math.GR cs.DM
null
Divisibility monoids (resp. Garside monoids) are a natural algebraic generalization of Mazurkiewicz trace monoids (resp. spherical Artin monoids), namely monoids in which the distributivity of the underlying lattices (resp. the existence of common multiples) is kept as an hypothesis, but the relations between the generators are not supposed to necessarily be commutations (resp. be of Coxeter type). Here, we show that the quasi-center of these monoids can be studied and described similarly, and then we exhibit the intersection between the two classes of monoids.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 13:53:18 GMT" } ]
2007-07-06T00:00:00
[ [ "Picantin", "Matthieu", "", "LIAFA" ] ]
0707.0786
Bozidar Mitrovic
Bozidar Mitrovic and Lee A. Rozema
On the correct formula for the lifetime broadened superconducting density of states
6 pages, 4 figures
null
10.1088/0953-8984/20/01/015215
null
cond-mat.supr-con
null
We argue that the well known Dynes formula [Dynes R C {\it et al.} 1978 {\it Phys. Rev. Lett.} {\bf 41} 1509] for the superconducting quasiparticle density of states, which tries to incorporate the lifetime broadening in an approximate way, cannot be justified microscopically for conventional superconductors. Instead, we propose a new simple formula in which the energy gap has a finite imaginary part $-\Delta_2$ and the quasiparticle energy is real. We prove that in the quasiparticle approximation 2$\Delta_2$ gives the quasiparticle decay rate at the gap edge for conventional superconductors. This conclusion does not depend on the nature of interactions that cause the quasiparticle decay. The new formula is tested on the case of a strong coupling superconductor Pb$_{0.9}$Bi$_{0.1}$ and an excellent agreement with theoretical predictions is obtained. While both the Dynes formula and the one proposed in this work give good fits and fit parameters for Pb$_{0.9}$Bi$_{0.1}$, only the latter formula can be justified microscopically.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:21:15 GMT" }, { "version": "v2", "created": "Wed, 14 Nov 2007 20:10:56 GMT" } ]
2009-11-13T00:00:00
[ [ "Mitrovic", "Bozidar", "" ], [ "Rozema", "Lee A.", "" ] ]
0707.0787
Tao Xu
Hai-Qiang Zhang, Juan Li, Tao Xu, Ya-Xing Zhang and Bo Tian
Symbolic-computation study of integrable properties for the (2+1)-dimensional Gardner equation with the two-singular-manifold method
null
null
null
null
nlin.SI nlin.PS
null
The singular manifold method from the Painleve analysis can be used to investigate many important integrable properties for the nonlinear partial differential equations.In this paper, the two-singular-manifold method is applied to the (2+1)-dimensional Gardner equation with two Painleve expansion branches to determine the Hirota bilinear form, Backlund transformation, Lax pairs and Darboux transformation. Based on the obtained Lax pairs, the binary Darboux transformation is constructed and the N N Grammian solution is also derived by performing the iterative algorithm Ntimes with symbolic computation.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:22:54 GMT" } ]
2007-07-06T00:00:00
[ [ "Zhang", "Hai-Qiang", "" ], [ "Li", "Juan", "" ], [ "Xu", "Tao", "" ], [ "Zhang", "Ya-Xing", "" ], [ "Tian", "Bo", "" ] ]
0707.0788
Luca Pasquini
L. Pasquini, M.P. Doellinger, A. Weiss, L. Girardi, C. Chavero, A.P. Hatzes, L. da Silva, J. Setiawan
Evolved stars hint to an external origin of enhanced metallicity in planet-hosting stars
A&A, in press
null
10.1051/0004-6361:20077814
null
astro-ph
null
Exo-planets are preferentially found around high metallicity main sequence stars. We aim at investigating whether evolved stars share this property, and what this tells about planet formation. Statistical tools and the basic concepts of stellar evolution theory are applied to published results as well as our own radial velocity and chemical analyses of evolved stars. We show that the metal distributions of planet-hosting (P-H) dwarfs and giants are different, and that the latter do not favor metal-rich systems. Rather, these stars follow the same age-metallicity relation as the giants without planets in our sample. The straightforward explanation is to attribute the difference between dwarfs and giants to the much larger masses of giants' convective envelopes. If the metal excess on the main sequence is due to pollution, the effects of dilution naturally explains why it is not observed among evolved stars. Although we cannot exclude other explanations, the lack of any preference for metal-rich systems among P-H giants could be a strong indication of the accretion of metal-rich material. We discuss further tests, as well as some predictions and consequences of this hypothesis.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:24:13 GMT" } ]
2009-11-13T00:00:00
[ [ "Pasquini", "L.", "" ], [ "Doellinger", "M. P.", "" ], [ "Weiss", "A.", "" ], [ "Girardi", "L.", "" ], [ "Chavero", "C.", "" ], [ "Hatzes", "A. P.", "" ], [ "da Silva", "L.", "" ], [ "Setiawan", "J.", "" ] ]
0707.0789
Vladimir Kartsovnik Dr.
W.I. Kartsovnik, V.V. Pelekh
On the mechanism of the flow of polymers
8 pages
null
null
null
cond-mat.soft
null
A non-Newtonian flow of a polymer melt is discussed. The description of the exponential decrease of the apparent viscosity by the well-known Eyring formula with an activation energy reduction proportional to the shear stress does not take into account specific features of the polymeric structure. We propose to modify the description of the macromolecular flow mechanism by including conformational changes of the polymeric chains. The elasticity of a strained polymeric chain, having an entropy origin, can be the reason of the reduction of the activation energy for the transition of a molecular-kinetic unit of the chain into a new equilibrium state in the flow direction during the thermal fluctuation. In that case, the activation energy of the transition should decrease by a value proportional to the reversible high-elastic component of the shear deformation caused by the flow of the polymer.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 17:35:33 GMT" } ]
2007-07-06T00:00:00
[ [ "Kartsovnik", "W. I.", "" ], [ "Pelekh", "V. V.", "" ] ]
0707.0790
Martin Feix
M. Feix, C. Fedeli and M. Bartelmann
Asymmetric Gravitational Lenses in TeVeS and Application to the Bullet Cluster
LaTex, 14 pages, 10 figures, references added, 2 figures removed, minor text changes to fit accepted version (A&A)
Astron.Astrophys. 480, 313-325 (2008)
10.1051/0004-6361:20078224
null
astro-ph
null
Aims: We explore the lensing properties of asymmetric matter density distributions in Bekenstein's Tensor-Vector-Scalar theory (TeVeS). Methods: Using an iterative Fourier-based solver for the resulting non-linear scalar field equation, we numerically calculate the total gravitational potential and derive the corresponding TeVeS lensing maps. Results: Considering variations on rather small scales, we show that the lensing properties significantly depend on the lens's extent along the line of sight. Furthermore, all simulated TeVeS convergence maps strongly track the dominant baryonic components, non-linear effects, being capable of counteracting this trend, turn out to be very small. Setting up a toy model for the cluster merger 1E0657-558, we infer that TeVeS cannot explain observations without assuming an additional dark mass component in both cluster centers, which is in accordance with previous work.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:34:34 GMT" }, { "version": "v2", "created": "Thu, 11 Oct 2007 00:13:02 GMT" } ]
2008-03-06T00:00:00
[ [ "Feix", "M.", "" ], [ "Fedeli", "C.", "" ], [ "Bartelmann", "M.", "" ] ]
0707.0791
William A. Atkinson
Yun Song, R. Wortis, W. A. Atkinson
Dynamical Mean Field Study of the Two-Dimensional Disordered Hubbard Model
5 pages, 4 figures. Revised version, In Press Phys. Rev. B
Phys. Rev. B 77, 054202 (2008)
10.1103/PhysRevB.77.054202
null
cond-mat.str-el cond-mat.dis-nn
null
We study the two-dimensional paramagnetic Anderson-Hubbard model using an extension of dynamical mean-field theory that allows us to treat disorder and strong electronic correlations on equal footing. We investigate the scaling of the inverse participation ratio at quarter- and half-filling and find a nonmonotonic dependence of the localization length on the interaction strength. We do not find evidence for an insulator-metal transition. The disorder potential becomes unscreened near the Mott transition. Furthermore, strong correlations suppress the Altshuler-Aronov density of states anomaly near half-filling.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:33:56 GMT" }, { "version": "v2", "created": "Mon, 28 Jan 2008 10:59:01 GMT" } ]
2009-11-13T00:00:00
[ [ "Song", "Yun", "" ], [ "Wortis", "R.", "" ], [ "Atkinson", "W. A.", "" ] ]
0707.0792
Matthias Punk
M. Punk, W. Zwerger
Theory of RF-spectroscopy of strongly interacting Fermions
revised version, 4 pages, 3 figures, RevTex4
null
10.1103/PhysRevLett.99.170404
null
cond-mat.other
null
We show that strong pairing correlations in Fermi gases lead to the appearance of a gap-like structure in the RF-spectrum, both in the balanced superfluid and in the normal phase above the Clogston-Chandrasekhar limit. The average RF-shift of a unitary gas is proportional to the ratio of the Fermi velocity and the scattering length with the final state. In the strongly imbalanced case, the RF-spectrum measures the binding energy of a minority atom to the Fermi sea of majority atoms. Our results provide a qualitative understanding of recent experiments by Schunck et.al.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:28:49 GMT" }, { "version": "v2", "created": "Tue, 18 Sep 2007 16:08:35 GMT" } ]
2009-11-13T00:00:00
[ [ "Punk", "M.", "" ], [ "Zwerger", "W.", "" ] ]
0707.0793
Francesco Becattini
F. Becattini, L. Ferroni (University of Florence and INFN)
The microcanonical ensemble of the ideal relativistic quantum gas with angular momentum conservation
38 pages; minor corrections to the formulae for the published version
Eur.Phys.J.C52:597-615,2007
10.1140/epjc/s10052-007-0403-7
null
nucl-th cond-mat.stat-mech
null
We derive the microcanonical partition function of the ideal relativistic quantum gas with fixed intrinsic angular momentum as an expansion over fixed multiplicities. We developed a group theoretical approach by generalizing known projection techniques to the Poincare' group. Our calculation is carried out in a quantum field framework and applies to particles with any spin. It extends known results in literature in that it does not introduce any large volume approximation and it takes particle spin fully into account. We provide expressions of the microcanonical partition function at fixed multiplicities in the limiting classical case of large volumes and large angular momenta and in the grand-canonical ensemble. We also derive the microcanonical partition function of the ideal relativistic quantum gas with fixed parity.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:40:19 GMT" }, { "version": "v2", "created": "Tue, 17 Jul 2007 17:13:16 GMT" }, { "version": "v3", "created": "Wed, 17 Oct 2007 16:12:39 GMT" } ]
2008-11-26T00:00:00
[ [ "Becattini", "F.", "", "University of Florence and INFN" ], [ "Ferroni", "L.", "", "University of Florence and INFN" ] ]
0707.0794
Uwe C. T\"auber
Uwe C. Tauber
Field-theoretic methods
Article for the Encyclopedia of Complexity and System Science, B. Meyers (Ed.), Springer-Verlag Berlin, 2008
Encyclopedia of Complexity and Systems Science, Robert A. Meyers (ed.), Springer; New York, 2009; pp. 3360-3374
10.1007/978-0-387-30440-3_200
null
cond-mat.stat-mech
null
Many complex systems are characterized by intriguing spatio-temporal structures. Their mathematical description relies on the analysis of appropriate correlation functions. Functional integral techniques provide a unifying formalism that facilitates the computation of such correlation functions and moments, and furthermore allows a systematic development of perturbation expansions and other useful approximative schemes. It is explained how nonlinear stochastic processes may be mapped onto exponential probability distributions, whose weights are determined by continuum field theory actions. Such mappings are madeexplicit for (1) stochastic interacting particle systems whose kinetics is defined through a microscopic master equation; and (2) nonlinear Langevin stochastic differential equations which provide a mesoscopic description wherein a separation of time scales between the relevant degrees of freedom and background statistical noise is assumed. Several well-studied examples are introduced to illustrate the general methodology.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:43:50 GMT" } ]
2009-11-12T00:00:00
[ [ "Tauber", "Uwe C.", "" ] ]
0707.0795
Prasanna Sahoo Dr
Valeriy A. Faiziev and Prasanna K. Sahoo
Stability of a functional equation of Deeba on semigroups
29 pages
null
null
null
math.CA math.FA
null
Let $S$ be a semigroup and $X$ a Banach space. The functional equation $\phi (xyz)+ \phi (x) + \phi (y) + \phi (z) = \phi (xy) + \phi (yz) + \phi (xz)$ is said to be stable for the pair $(X, S)$ if and only if $f: S\to X$ satisfying $\| f(xyz)+f(x) + f(y) + f(z) - f(xy)- f(yz)-f(xz)\| \leq \delta $ for some positive real number $\delta$ and all $x, y, z \in S$, there is a solution $\phi : S \to X$ such that $f-\phi$ is bounded. In this paper, among others, we prove the following results: 1) this functional equation, in general, is not stable on an arbitrary semigroup; 2) this equation is stable on periodic semigroups; 3) this equation is stable on abelian semigroups; 4) any semigroup with left (or right) law of reduction can be embedded into a semigroup with left (or right) law of reduction where this equation is stable.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:50:35 GMT" } ]
2007-07-06T00:00:00
[ [ "Faiziev", "Valeriy A.", "" ], [ "Sahoo", "Prasanna K.", "" ] ]
0707.0796
Alessandro Nordio
A. Nordio, C.-F. Chiasserini, E. Viterbo
Performance of Linear Field Reconstruction Techniques with Noise and Uncertain Sensor Locations
null
null
10.1109/TSP.2008.924865
null
cs.OH
null
We consider a wireless sensor network, sampling a bandlimited field, described by a limited number of harmonics. Sensor nodes are irregularly deployed over the area of interest or subject to random motion; in addition sensors measurements are affected by noise. Our goal is to obtain a high quality reconstruction of the field, with the mean square error (MSE) of the estimate as performance metric. In particular, we analytically derive the performance of several reconstruction/estimation techniques based on linear filtering. For each technique, we obtain the MSE, as well as its asymptotic expression in the case where the field number of harmonics and the number of sensors grow to infinity, while their ratio is kept constant. Through numerical simulations, we show the validity of the asymptotic analysis, even for a small number of sensors. We provide some novel guidelines for the design of sensor networks when many parameters, such as field bandwidth, number of sensors, reconstruction quality, sensor motion characteristics, and noise level of the measures, have to be traded off.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:58:24 GMT" } ]
2009-11-13T00:00:00
[ [ "Nordio", "A.", "" ], [ "Chiasserini", "C. -F.", "" ], [ "Viterbo", "E.", "" ] ]
0707.0797
Barbara Mele
Emidio Gabrielli, Barbara Mele, and Johan Rathsman
Higgs boson plus photon production at the LHC: a clean probe of the b-quark parton densities
10 pages, 4 figures, a few comments and 3 references added at the end. To appear in Physical Review D
Phys.Rev.D77:015007,2008
10.1103/PhysRevD.77.015007
null
hep-ph
null
Higgs boson production in association with a high pT photon at the CERN Large Hadron Collider is analyzed, in the framework of the MSSM model, for the heavier neutral Higgs bosons. The request of an additional photon in the exclusive Higgs boson final state selects b-quark pairs among the possible initial partonic states, since gluon-gluon initial states are not allowed by C-parity conservation. Hence, the measurement of cross sections for neutral Higgs boson plus photon production can provide a clean probe of the b-quark density in the proton as well as of the b-quark Yukawa coupling. The suppression of the production rates by the b-quark electromagnetic coupling can be compensated by the enhanced Higgs boson Yukawa coupling to b's in the large tan(beta) regime. The Higgs boson decay into a tau-lepton pair is considered, and irreducible backgrounds with corresponding signal significances are evaluated.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 14:58:40 GMT" }, { "version": "v2", "created": "Tue, 4 Dec 2007 12:40:46 GMT" } ]
2008-11-26T00:00:00
[ [ "Gabrielli", "Emidio", "" ], [ "Mele", "Barbara", "" ], [ "Rathsman", "Johan", "" ] ]
0707.0798
Markus Kindermann
M. Kindermann
Hall effect between parallel quantum wires
5 pages, 2 figures, missing summation added to Eq. (6), more thorough discussion of the experimental signatures
Europhys. Lett. 83, 47002 (2008)
10.1209/0295-5075/83/47002
null
cond-mat.mes-hall cond-mat.str-el
null
We study theoretically the parallel quantum wires of the experiment by Auslaender et al. [Science 308, 88 (2005)] at low electron density. It is shown that a Hall effect as observed in two- or three-dimensional electron systems develops as one of the two wires enters the spin-incoherent regime of small spin bandwidth. This together with magnetic field dependent tunneling exponents clearly identifies spin-incoherence in such experiments and it serves to distinguish it from disorder effects.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:43:38 GMT" }, { "version": "v2", "created": "Wed, 12 Sep 2007 19:17:01 GMT" } ]
2009-11-13T00:00:00
[ [ "Kindermann", "M.", "" ] ]
0707.0799
Xinjia Chen
Xinjia Chen, Kemin Zhou and Jorge Aravena
A New Family of Unitary Space-Time Codes with a Fast Parallel Sphere Decoder Algorithm
66 pages, 7 figures
IEEE Transactions on Information Theory, vol. 52, pp. 115-140, January 2006
null
null
cs.IT math.IT
null
In this paper we propose a new design criterion and a new class of unitary signal constellations for differential space-time modulation for multiple-antenna systems over Rayleigh flat-fading channels with unknown fading coefficients. Extensive simulations show that the new codes have significantly better performance than existing codes. We have compared the performance of our codes with differential detection schemes using orthogonal design, Cayley differential codes, fixed-point-free group codes and product of groups and for the same bit error rate, our codes allow smaller signal to noise ratio by as much as 10 dB. The design of the new codes is accomplished in a systematic way through the optimization of a performance index that closely describes the bit error rate as a function of the signal to noise ratio. The new performance index is computationally simple and we have derived analytical expressions for its gradient with respect to constellation parameters. Decoding of the proposed constellations is reduced to a set of one-dimensional closest point problems that we solve using parallel sphere decoder algorithms. This decoding strategy can also improve efficiency of existing codes.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 19:01:53 GMT" } ]
2008-05-12T00:00:00
[ [ "Chen", "Xinjia", "" ], [ "Zhou", "Kemin", "" ], [ "Aravena", "Jorge", "" ] ]
0707.0800
Chung Yue Hui David
C. Y. Hui, W. Becker (MPE)
Resolving the bow-shock nebula around the old pulsar PSR B1929+10 with multi-epoch Chandra observations
Accepted by A&A, revised in accordance with referee's comments
null
10.1051/0004-6361:20078227
null
astro-ph
null
We have studied the nearby old pulsar PSR B1929+10 and its surrounding interstellar medium utilizing the sub-arcsecond angular resolution of the Chandra X-ray Observatory. The Chandra data are found to be fully consistent with the results obtained from deep XMM-Newton observations as far as the pulsar is concerned. We confirm the non-thermal emission nature of the pulsar's X-radiation. In addition to the X-ray trail already seen in previous observations by the ROSAT and XMM-Newton X-ray observatories, we discovered an arc-like nebula surrounding the pulsar. We interpret the feature as a bow-shock nebula and discuss its energetics in the context of standard shock theory.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:03:43 GMT" }, { "version": "v2", "created": "Thu, 29 May 2008 15:51:08 GMT" } ]
2009-11-13T00:00:00
[ [ "Hui", "C. Y.", "", "MPE" ], [ "Becker", "W.", "", "MPE" ] ]
0707.0801
Fuqiang Wang
Fuqiang Wang
In-Medium Properties of Jets
Invited talk at Quark Matter 2006
J.Phys.G34:S337-S344,2007
10.1088/0954-3899/34/8/S20
null
nucl-ex
null
Modifications of jet-like azimuthal correlations have revealed novel properties of the medium created in relativistic heavy-ion collisions. Experimental results on jet-like 2- and 3-particle correlations, specificly "punch-through" at high transverse momentum, broadening at low and modest transverse momentum, and particularly the possible experimental evidence for conical flow, are reviewed. Future prospects of jet-like correlations and their physics potential are discussed.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:09:40 GMT" } ]
2008-11-26T00:00:00
[ [ "Wang", "Fuqiang", "" ] ]
0707.0802
Patricia Reynier
Dinu Coltuc, Jean-Marc Chassery (GIPSA-lab)
Very fast watermarking by reversible contrast mapping
null
IEEE Signal Processing Letters 14, 4 (04/2007) pp 255-258
10.1109/LSP.2006.884895
null
cs.MM cs.CR cs.CV cs.IT math.IT
null
Reversible contrast mapping (RCM) is a simple integer transform that applies to pairs of pixels. For some pairs of pixels, RCM is invertible, even if the least significant bits (LSBs) of the transformed pixels are lost. The data space occupied by the LSBs is suitable for data hiding. The embedded information bit-rates of the proposed spatial domain reversible watermarking scheme are close to the highest bit-rates reported so far. The scheme does not need additional data compression, and, in terms of mathematical complexity, it appears to be the lowest complexity one proposed up to now. A very fast lookup table implementation is proposed. Robustness against cropping can be ensured as well.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:11:24 GMT" } ]
2009-11-13T00:00:00
[ [ "Coltuc", "Dinu", "", "GIPSA-lab" ], [ "Chassery", "Jean-Marc", "", "GIPSA-lab" ] ]
0707.0803
Gestur Olafsson
Gestur Olafsson and Henrik Schlichtkrull
Representation theory, Radon transform and the heat equation on a Riemannian symmetric space
null
null
null
null
math.RT
null
Let X=G/K be a Riemannian symmetric space of the noncompact type. We give a short exposition of the representation theory related to X, and discuss its holomorphic extension to the complex crown, a G-invariant subdomain in the complexified symmetric space X_\C=G_\C/K_\C. Applications to the heat transform and the Radon transform for X are given.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:11:42 GMT" } ]
2007-07-06T00:00:00
[ [ "Olafsson", "Gestur", "" ], [ "Schlichtkrull", "Henrik", "" ] ]
0707.0804
Brigitte Gaillard
M. Boos (DEPE-Iphc), C. Zimmer (DEPE-Iphc), A. Carriere (DEPE-Iphc), J.P. Robin (DEPE-Iphc), O. Petit (DEPE-Iphc)
Post-hatching parental care behaviour and hormonal status in a precocial bird
null
Behavioural Processes (18/05/2007) sous presse
10.1016/j.beproc.2007.05.003
null
q-bio.PE
null
In birds, the link between parental care behaviour and prolactin release during incubation persists after hatching in altricial birds, but has never been precisely studied during the whole rearing period in precocial species, such as ducks. The present study aims to understand how changes in parental care after hatching are related to circulating prolactin levels in mallard hens rearing ducklings. Blood was sampled in hens over at least 13 post-hatching weeks and the behaviour of the hens and the ducklings was recorded daily until fledging. Contacts between hens and the ducklings, leadership of the ducklings and gathering of them steadily decreased over post-hatching time. Conversely, resting, preening and agonistic behaviour of hens towards ducklings increased. Plasma prolactin concentrations remained at high levels after hatching and then fell after week 6 when body mass and structural size of the young were close to those of the hen. Parental care behaviour declined linearly with brood age, showed a disruption of the hen-brood bond at week 6 post-hatching and was related to prolactin concentration according to a sigmoid function. Our results suggest that a definite threshold in circulating prolactin is necessary to promote and/or to maintain post-hatching parental care in ducks.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:12:49 GMT" } ]
2007-07-06T00:00:00
[ [ "Boos", "M.", "", "DEPE-Iphc" ], [ "Zimmer", "C.", "", "DEPE-Iphc" ], [ "Carriere", "A.", "", "DEPE-Iphc" ], [ "Robin", "J. P.", "", "DEPE-Iphc" ], [ "Petit", "O.", "", "DEPE-Iphc" ] ]
0707.0805
Xinjia Chen
Xinjia Chen
A New Generalization of Chebyshev Inequality for Random Vectors
7 pages, 1 figure; added some references
null
null
null
math.ST cs.LG math.PR stat.AP stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we derive a new generalization of Chebyshev inequality for random vectors. We demonstrate that the new generalization is much less conservative than the classical generalization.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:28:05 GMT" }, { "version": "v2", "created": "Fri, 24 Jun 2011 15:08:17 GMT" } ]
2013-11-05T00:00:00
[ [ "Chen", "Xinjia", "" ] ]
0707.0806
Daniel Beltita
Daniel Beltita and Jose E. Gale
Holomorphic geometric models for representations of $C^*$-algebras
45 pages
null
null
null
math.OA math.DG
null
Representations of $C^*$-algebras are realized on section spaces of holomorphic homogeneous vector bundles. The corresponding section spaces are investigated by means of a new notion of reproducing kernel, suitable for dealing with involutive diffeomorphisms defined on the base spaces of the bundles. Applications of this technique to dilation theory of completely positive maps are explored and the critical role of complexified homogeneous spaces in connection with the Stinespring dilations is pointed out. The general results are further illustrated by a discussion of several specific topics, including similarity orbits of representations of amenable Banach algebras, similarity orbits of conditional expectations, geometric models of representations of Cuntz algebras, the relationship to endomorphisms of ${\mathcal B}({\mathcal H})$, and non-commutative stochastic analysis.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:17:49 GMT" }, { "version": "v2", "created": "Fri, 22 Feb 2008 05:58:43 GMT" } ]
2008-02-22T00:00:00
[ [ "Beltita", "Daniel", "" ], [ "Gale", "Jose E.", "" ] ]
0707.0807
Nikulov Alexey
S.V. Dubonos, V.L. Gurtovoi, A.V. Nikulov, and V.A. Tulin
Can dc voltage proportional to the persistent current be observed on segment of asymmetric mesoscopic ring?
3 pages, 2 figures
in the Proceedings of 15th International Symposium "Nanostructures: Physics and Technology" St Petersburg: Ioffe Institute, p. 60 (2007)
null
null
cond-mat.supr-con cond-mat.mes-hall
null
In order to clear up a question on possibility of a dc voltage proportional to the persistent current in normal metal and semiconductor mesoscopic loops conjectural causes of this phenomenon observed in superconductor loops is investigated.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:18:08 GMT" } ]
2007-07-06T00:00:00
[ [ "Dubonos", "S. V.", "" ], [ "Gurtovoi", "V. L.", "" ], [ "Nikulov", "A. V.", "" ], [ "Tulin", "V. A.", "" ] ]
0707.0808
Patrick C. McGuire
Alexandra Bartolo, Patrick C. McGuire, Kenneth P. Camilleri, Christopher Spiteri, Jonathan C. Borg, Philip J. Farrugia, Jens Ormo, Javier Gomez-Elvira, Jose Antonio Rodriguez-Manfredi, Enrique Diaz-Martinez, Helge Ritter, Robert Haschke, Markus Oesker, Joerg Ontrup
The Cyborg Astrobiologist: Porting from a wearable computer to the Astrobiology Phone-cam
15 pages, 4 figures, accepted for publication in the International Journal of Astrobiology
International Journal of Astrobiology, vol. 6, issue 4, pp. 255-261 (2007)
10.1017/S1473550407003862
null
cs.CV astro-ph cs.AI cs.CE cs.HC cs.NI cs.RO cs.SE
null
We have used a simple camera phone to significantly improve an `exploration system' for astrobiology and geology. This camera phone will make it much easier to develop and test computer-vision algorithms for future planetary exploration. We envision that the `Astrobiology Phone-cam' exploration system can be fruitfully used in other problem domains as well.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:19:37 GMT" } ]
2010-01-08T00:00:00
[ [ "Bartolo", "Alexandra", "" ], [ "McGuire", "Patrick C.", "" ], [ "Camilleri", "Kenneth P.", "" ], [ "Spiteri", "Christopher", "" ], [ "Borg", "Jonathan C.", "" ], [ "Farrugia", "Philip J.", "" ], [ "Ormo", "Jens", "" ], [ "Gomez-Elvira", "Javier", "" ], [ "Rodriguez-Manfredi", "Jose Antonio", "" ], [ "Diaz-Martinez", "Enrique", "" ], [ "Ritter", "Helge", "" ], [ "Haschke", "Robert", "" ], [ "Oesker", "Markus", "" ], [ "Ontrup", "Joerg", "" ] ]
0707.0809
Patrizia Michetti
F. Marinetti, Ll. Uranga-Pi\~na, E. Coccia, D. L\'opez-Dur\'an, E. Bodo, F.A. Gianturco
Microsolvation of cationic dimers in $^4$He droplets: geometries of A$_2^+$(He)$_N$ (A=Li,Na,K) from optimized energies
null
null
10.1021/jp0748361
null
physics.chem-ph
null
Ab initio computed interaction forces are employed in order to describe the microsolvation of the A$_2^+(^2\Sigma)$ (A=Li,Na,K) molecular ion in $^4$He clusters of small variable size. The minimum energy structures are obtained by performing energy minimization based on a genetic algorithm approach. The symmetry features of the collocation of solvent adatoms around the dimeric cation are analyzed in detail, showing that the selective growth of small clusters around the two sides of the ion during the solvation process is a feature common to all three dopants.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:19:59 GMT" } ]
2016-09-28T00:00:00
[ [ "Marinetti", "F.", "" ], [ "Uranga-Piña", "Ll.", "" ], [ "Coccia", "E.", "" ], [ "López-Durán", "D.", "" ], [ "Bodo", "E.", "" ], [ "Gianturco", "F. A.", "" ] ]
0707.0810
Alfred Tillich
A. Tillich, U. Heber, S. J. O'Toole, R. {\O}stensen, S. Schuh
The MSST Campaign: II.Effective temperature and gravity variations in the multi-periodic pulsating subdwarf B star PG1605+072
10 pages, 9 figures, Accepted for publication in A&A
null
10.1051/0004-6361:20077949
null
astro-ph
null
Stellar oscillations are an important tool to probe the interior of a star. Subdwarf B stars are core helium burning objects, but their formation is poorly understood as neither single star nor binary evolution can fully explain their observed properties. Since 1997 an increasing number of sdB stars has been found to pulsate forming two classes of stars (the V361 Hya and V1093 Her stars). We focus on the bright V 361 Hya star PG1605+072 to characterize its frequency spectrum. While most previous studies relied on light variations, we have measured radial velocity variations for as much as 20 modes. In this paper we aim at characterizing the modes from atmospheric parameter and radial velocity variations. Time resolved spectroscopy ($\approx$9000 spectra) has been carried out to detect line profile variations from which variations of the effective temperature and gravity are extracted by means of a quantitative spectral analysis. We measured variations of effective temperatures and gravities for eight modes with semi-amplitudes ranging from $\Delta T_{\rm{eff}}=880$ K to as small as 88 K and $\Delta\log{g}$ of 0.08 dex to as low as 0.008 dex. Gravity and temperature vary almost in phase, whereas phase lags are found between temperature and radial velocity. This profound analysis of a unique data set serves as sound basis for the next step towards an identification of pulsation modes. As rotation may play an important role the modelling of pulsation modes is challenging but feasible.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:26:29 GMT" } ]
2009-11-13T00:00:00
[ [ "Tillich", "A.", "" ], [ "Heber", "U.", "" ], [ "O'Toole", "S. J.", "" ], [ "Østensen", "R.", "" ], [ "Schuh", "S.", "" ] ]
0707.0811
Dmitri Kharzeev
D. Kharzeev, E. Levin and M. Nardi
Hadron multiplicities at the LHC
2 pages, 2 figures, talk at "Heavy Ion Collisions at the LHC: Last Call for Predictions" Workshop, CERN, May 14 - June 8, 2007, to appear in the Proceedings
null
null
BNL-NT-07/31
hep-ph
null
We present the predictions for hadron multiplicities in pp, pA and AA collisions at the LHC based on our approach to the Color Glass Condensate.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 19:01:49 GMT" } ]
2007-07-06T00:00:00
[ [ "Kharzeev", "D.", "" ], [ "Levin", "E.", "" ], [ "Nardi", "M.", "" ] ]
0707.0812
Chuan Hung Chen
Chuan-Hung Chen, Chao-Qiang Geng, Soo-Hyeon Nam
Comment on ``New Physics Contributions to the Lifetime Difference in $D^0-\bar D^{0}$ mixing''
2 pages
Phys.Rev.Lett.99:019101,2007
10.1103/PhysRevLett.99.019101
null
hep-ph
null
We find that in the nonmanifest left-right (LR) model, an important LR mixing effect was not considered in the paper by E. Golowich, S. Pakvasa, and A. Petrov, Phys. Rev. Lett. 98, 181801 (2007).
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:35:27 GMT" } ]
2008-11-26T00:00:00
[ [ "Chen", "Chuan-Hung", "" ], [ "Geng", "Chao-Qiang", "" ], [ "Nam", "Soo-Hyeon", "" ] ]
0707.0813
Amine Asselah
Amine Asselah
Large Deviations Principle for Self-Intersection Local Times for random walk in dimension d>4
45 pages, 2 figures, thorough revision
null
null
null
math.PR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a large deviations principle for the self-intersection local times for a symmetric random walk in dimension d>4. As an application, we obtain moderate deviations for random walk in random sceneries in some region of parameters.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:34:15 GMT" }, { "version": "v2", "created": "Sat, 15 Sep 2007 12:52:07 GMT" }, { "version": "v3", "created": "Sun, 28 Dec 2008 12:46:01 GMT" } ]
2008-12-30T00:00:00
[ [ "Asselah", "Amine", "" ] ]
0707.0814
Dan Allen
D. G. Allen, L. Persechini, S. Takahashi, G. Ramina, M. S. Sherwin
A diffraction-compensating 0-25 ns free space terahertz delay line for coherent quantum control
null
null
10.1063/1.2804111
null
physics.optics
null
Free space delay lines provide pulses of variable time spacing for optical experiments such as pump-probe spectroscopy and coherent quantum control, including spin and photon echo techniques. However, in the terahertz (THz) region of the spectrum, beam divergence due to diffraction limits the useful length of traditional free space delay lines. We present a novel double-folded variable delay line for light in the frequency range 0.24-1.2 THz, which incorporates a symmetric arrangement of lenses whose spacing can be adjusted to compensate for diffraction at each delay. Scalable for use in other wavelength regimes, the design relays an input Gaussian beam waist to the output with up to 25 ns (~8 m) total delay and is enclosed in a desiccated volume of <0.5 m^3. The delay line can deliver two or three pulses with relative amplitudes controlled via variable spacing silicon etalon beam splitters. Beam profiles of a 0.24 THz beam show good agreement with calculations at long delays, with insertion loss per delay stage of~3 dB.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:42:06 GMT" } ]
2009-11-13T00:00:00
[ [ "Allen", "D. G.", "" ], [ "Persechini", "L.", "" ], [ "Takahashi", "S.", "" ], [ "Ramina", "G.", "" ], [ "Sherwin", "M. S.", "" ] ]
0707.0815
Fuqiang Wang
Fuqiang Wang (for the STAR Collaboration)
Forward- and Mid-Rapidity Jet-like correlations
Invited talk at the XIth International Workshop on Correlation and Fluctuation in Multiparticle Production, Hangzhou, China, November 2007
Int.J.Mod.Phys. E16 (2008) 3168-3175
10.1142/S0218301307009166
null
nucl-ex
null
Mid-rapidity azimuthal correlations probe di-jets originating mainly from gluon-gluon hard-scattering. Measurements of such correlations have revealed significant (gluon-)jet modification in central Au+Au collisions. Azimuthal correlations of hadrons at forward rapidity with a mid-rapidity high-$\pt$ hadron, on the other hand, probe asymmetric partonic scatterings involving large-x quarks and small-x gluons. We present preliminary results from STAR on correlations of charged hadrons at forward rapidity in the forward TPCs ($2.7<|\eta|<3.9$, $\pt<2$ GeV/$c$) with high-$\pt$ charged hadrons at mid-rapidity from the main TPC ($|\eta|<1$, $\pt>3$ GeV/$c$) in $pp$, d+Au, and Au+Au collisions at $\snn=200$ GeV. The implications of the results for small-x gluon distributions (Color Glass Condensate formation) and the energy loss of quark jets at forward rapidity in nuclear medium are discussed. %Their measurements in d+Au collisions, separately at the d-side and the Au-side, may be sensitive to Color Glass Condensate in the Au-nucleus. Their measurements in Au+Au collisions may probe quark-jet modification in nuclear medium.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:43:44 GMT" } ]
2019-08-13T00:00:00
[ [ "Wang", "Fuqiang", "", "for the STAR Collaboration" ] ]
0707.0816
Jason Tumlinson
Jason Tumlinson (Yale University)
Carbon-Enhanced Hyper-metal-poor Stars and the Stellar IMF at Low Metallicity
11 pages emulateapj text including three figures, accepted for publication in ApJ v666 (Sept 2007). A companion paper to 0706.2903
Astrophys.J.665:1361-1370,2007
10.1086/519917
null
astro-ph
null
The two known ``hyper-metal-poor'' (HMP) stars, HE0107-5240 and HE1327-2326, have extremely high enhancements of the light elements C, N, and O relative to Fe and appear to represent a statistically significant excess population relative to the halo metallicity distribution extrapolated from [Fe/H] > -3. This study weighs the available evidence for and against three hypothetical origins for these stars: (1) that they formed from gas enriched by a primordial ``faint supernova'', (2) that they formed from gas enriched by core-collapse supernovae and C-rich gas ejected in rotation-driven winds from massive stars, and (3) that they formed as the low-mass secondaries in binary systems at Z ~ 10^{-5.5} Zsun and acquired their light-element enhancements from an intermediate-mass companion as it passed through an AGB phase. The observations interpreted here, especially the depletion of lithium seen in HE1327-2326, favor the binary mass-transfer hypothesis. If HE0107-5240 and HE1327-2326 formed in binary systems, the statistically significant absence of isolated and/or C-normal stars at similar [Fe/H] implies that low-mass stars could form at that metallicity, but that masses M ~< 1.4 Msun were disfavored in the IMF. This result is also explained if the abundance-derived top-heavy IMF for primordial stars persists to [Fe/H] ~ -5.5. This finding indicates that low-mass star formation was possible at extremely low metallicity, and that the typical stellar mass may have had a complex dependence on metallicity rather than a sharp transition driven solely by gas cooling.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:47:20 GMT" } ]
2011-02-11T00:00:00
[ [ "Tumlinson", "Jason", "", "Yale University" ] ]
0707.0817
Wei-shui Xu
Yi-hong Gao, Wei-shui Xu and Ding-fang Zeng
Viscosity and jet quenching from holographic model
5 pages, minor changes and references added
null
null
null
hep-ph
null
We consider the backreaction of the fundamental flavor degrees of freedom on the AdS$_5$-Schwarz background, and calculate their contributions to the shear viscosity and jet-quenching parameter of the thermal quark-gluon plasma.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:01:13 GMT" }, { "version": "v2", "created": "Sun, 23 Sep 2007 14:57:23 GMT" } ]
2007-09-23T00:00:00
[ [ "Gao", "Yi-hong", "" ], [ "Xu", "Wei-shui", "" ], [ "Zeng", "Ding-fang", "" ] ]
0707.0818
Serguei Popov
Francis Comets, Serguei Popov, Marina Vachkovskaia
The number of open paths in an oriented $\rho$-percolation model
30 pages, 2 figures
Journal of Statistical Physics, v. 131, p. 357-379, 2008
10.1007/s10955-008-9506-2
null
math.PR
null
We study the asymptotic properties of the number of open paths of length $n$ in an oriented $\rho$-percolation model. We show that this number is $e^{n\alpha(\rho)(1+o(1))}$ as $n \to \infty$. The exponent $\alpha$ is deterministic, it can be expressed in terms of the free energy of a polymer model, and it can be explicitely computed in some range of the parameters. Moreover, in a restricted range of the parameters, we even show that the number of such paths is $n^{-1/2} W e^{n\alpha(\rho)}(1+o(1))$ for some nondegenerate random variable $W$. We build on connections with the model of directed polymers in random environment, and we use techniques and results developed in this context.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:50:06 GMT" } ]
2012-01-31T00:00:00
[ [ "Comets", "Francis", "" ], [ "Popov", "Serguei", "" ], [ "Vachkovskaia", "Marina", "" ] ]
0707.0819
Juan Carlos Su\'arez
J.C. Su\'arez (1,2), E. Michel (2), G. Houdek (3), F. P\'erez Hern\'andez (4,5), Y. Lebreton (6) ((1) Instituto de Astrof\'isica de Andaluc\'ia (CSIC) (2) LESIA, Observatoire de Paris-Meudon (3) Institute of Astronomy, University of Cambridge (4) Instituto de Astrof\'isica de Canarias (IAC) (5) Departamento de Astrof\'isica, Universidad de La Laguna (6) GEPI, Observatoire de Paris-Meudon)
Asteroseismology of delta Scuti stars in open clusters: Praesepe
6 pages, 1 figure. Accepted for publication in Communications in Asteroseismology
null
10.1553/cia151s39
null
astro-ph
null
The present paper provides a general overview of the asteroseismic potential of delta Scuti stars in clusters, in particular focusing on convection diagnostics. We give a summarise of the last results obtained by the authors for the Praesepe cluster of which five delta Scuti stars are analysed. In that work, linear analysis is confronted with observations, using refined descriptions for the effects of rotation on the determination of the global stellar parameters and on the adiabatic oscillation frequency computations. A single, complete, and coherent solution for all the selected stars is found, which lead the authors to find important restrictions to the convection description for a certain range of effective temperatures. Furthermore, the method used allowed to give an estimate of the global parameters of the selected stars and constrain the cluster.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 15:54:58 GMT" } ]
2016-08-14T00:00:00
[ [ "Suárez", "J. C.", "" ], [ "Michel", "E.", "" ], [ "Houdek", "G.", "" ], [ "Hernández", "F. Pérez", "" ], [ "Lebreton", "Y.", "" ] ]
0707.0820
Torsten Rudolf
T. Rudolf, Ch. Kant, F. Mayr, and A. Loidl
Magnetic-order induced phonon splitting in MnO from far-infrared spectroscopy
5 pages, 4 figures
Phys. Rev. B 77, 024421 (2008)
10.1103/PhysRevB.77.024421
null
cond-mat.str-el
null
Detailed far-infrared spectra of the optical phonons are reported for antiferromagnetic MnO. Eigenfrequencies, phonon damping and effective plasma frequencies are studied as a function of temperature. Special attention is paid to the phonon splitting at the antiferromagnetic phase transition. The results are compared to recent experimental and theoretical studies of the spin-phonon coupling in frustrated magnets, which are explained in terms of a spin-driven Jahn-Teller effect, and to ab initio and model calculations, which predict phonon splitting induced by magnetic order.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:02:48 GMT" }, { "version": "v2", "created": "Mon, 15 Oct 2007 13:51:27 GMT" } ]
2008-06-26T00:00:00
[ [ "Rudolf", "T.", "" ], [ "Kant", "Ch.", "" ], [ "Mayr", "F.", "" ], [ "Loidl", "A.", "" ] ]
0707.0821
Juan Carlos Su\'arez
J. C. Su\'arez (1,2), R. Garridol (1), A. Moya (1) ((1)Instituto de Astrof\'isica de Andaluc\'ia (CSIC), (2) LESIA, Observatoire de Paris-Meudon)
Analysis of radial fundamental-to-first overtone period ratios in the presence of near degeneracy
5 pages,1 figure. Accepted for publication in Communications in Asteroseismology
null
null
null
astro-ph
null
In the present work we provide the preliminary results obtained when analysing the rotational Petersen diagrams when including the effects of near degeneracy. We found that near degeneracy affects significantly the fundamental-to-first overtone period ratios, showing wriggles in the Petersen diagrams. Analysis of such wriggles reveals that they are mainly caused by the avoided-crossing phenomenon. The size of wriggles seems to increase with the rotational velocity and could, in certain cases, invalidate any accurate mass and/or metallicity determinations. Nevertheless, deep analysis of near degeneracy effects may allow us to obtain additional information on the mode identification of the radial modes and their corresponding coupled pairs, which would allow us to constrain the modelling.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:07:45 GMT" } ]
2016-08-14T00:00:00
[ [ "Suárez", "J. C.", "" ], [ "Garridol", "R.", "" ], [ "Moya", "A.", "" ] ]
0707.0822
Fran\c{c}ois Gautero
Francois Gautero and Martin Lustig
The mapping-torus of a free group automorphism is hyperbolic relative to the canonical subgroups of polynomial growth
40 pages, no figure. Differences with respect to the first version: there is now an Appendix about $\beta$-train tracks, written by the second author. A Corollary about Rapid Decay for free-by-cyclic groups has been added
null
null
null
math.GR math.GT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We prove that the mapping torus group $\FN \rtimes_{\alpha} \Z$ of any automorphism $\alpha$ of a free group $\FN$ of finite rank $n \geq 2$ is weakly hyperbolic relative to the canonical (up to conjugation) family $\mathcal H(\alpha)$ of subgroups of $\FN$ which consists of (and contains representatives of all) conjugacy classes that grow polynomially under iteration of $\alpha$. Furthermore, we show that $\FN \rtimes_{\alpha} \Z$ is strongly hyperbolic relative to the mapping torus of the family $\mathcal H(\alpha)$. As an application, we use a result of Drutu-Sapir to deduce that $\FN \rtimes_{\alpha} \Z$ has Rapic Decay.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:11:00 GMT" }, { "version": "v2", "created": "Sun, 26 Oct 2008 18:06:20 GMT" } ]
2008-10-26T00:00:00
[ [ "Gautero", "Francois", "" ], [ "Lustig", "Martin", "" ] ]
0707.0823
Xinjia Chen
Xinjia Chen, Kemin Zhou and Jorge L. Aravena
A Statistical Theory for the Analysis of Uncertain Systems
32 pages, 15 figures
Proceeding of Joint Meeting of Statistics, pp. 1656--1663, Salt Lake City, 2007
null
null
stat.AP math.DS
null
This paper addresses the issues of conservativeness and computational complexity of probabilistic robustness analysis. We solve both issues by defining a new sampling strategy and robustness measure. The new measure is shown to be much less conservative than the existing one. The new sampling strategy enables the definition of efficient hierarchical sample reuse algorithms that reduce significantly the computational complexity and make it independent of the dimension of the uncertainty space. Moreover, we show that there exists a one to one correspondence between the new and the existing robustness measures and provide a computationally simple algorithm to derive one from the other.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:12:32 GMT" } ]
2008-05-12T00:00:00
[ [ "Chen", "Xinjia", "" ], [ "Zhou", "Kemin", "" ], [ "Aravena", "Jorge L.", "" ] ]
0707.0824
Sergey Afonin
S. S. Afonin
Properties of new unflavored mesons below 2.4 GeV
5 pages, to appear in Phys. Rev. C XX, 005200 (2007)
Phys.Rev.C76:015202,2007
10.1103/PhysRevC.76.015202
null
hep-ph
null
The global features of spectrum of highly excited light nonstrange mesons can be well understood within both chiral symmetry restoration scenario combined with the relation $M^2\sim J+n$ and within nonrelativistic description based on the relation $M^2\sim L+n$. The predictions of these two alternative classifications for missing states are different and only future experiments can distinguish between the two. We elaborate and compare systematically the predictions of both schemes, which may serve as a suggestion for future experiments devoted to the search for missing states.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:38:45 GMT" } ]
2008-11-26T00:00:00
[ [ "Afonin", "S. S.", "" ] ]
0707.0825
Alexei Deriglazov A
A. A. Deriglazov
Construction of Lagrangian local symmetries for general quadratic theory
null
Int.J.Mod.Phys.A22:2105-2118,2007
10.1142/S0217751X07035185
null
hep-th math-ph math.MP
null
We propose a procedure which allows one to construct local symmetry generators of general quadratic Lagrangian theory. Manifest recurrence relations for generators in terms of so-called structure matrices of the Dirac formalism are obtained. The procedure fulfilled in terms of initial variables of the theory, and do not implies either separation of constraints on first and second class subsets or any other choice of basis for constraints.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 19:20:51 GMT" } ]
2008-11-26T00:00:00
[ [ "Deriglazov", "A. A.", "" ] ]
0707.0826
Victor Malyshev
J. A. Klugkist, V. A. Malyshev, J. Knoester
Selection of dominant multi-exciton transitions in disordered linear J-aggregates
8 pages, 2 figures, accepted to Journal of Luminescence
J. Lumin.128, 945 (2008)
10.1016/j.jlumin.2007.11.052
null
cond-mat.dis-nn cond-mat.mtrl-sci
null
We show that the third-order optical response of disordered linear J-aggregates can be calculated by considering only a limited number of transitions between (multi-) exciton states. We calculate the pump-probe absorption spectrum resulting from the truncated set of transitions and show that, apart from the blue wing of the induced absorption peak, it agrees well with the exact spectrum.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:29:28 GMT" } ]
2009-11-13T00:00:00
[ [ "Klugkist", "J. A.", "" ], [ "Malyshev", "V. A.", "" ], [ "Knoester", "J.", "" ] ]
0707.0827
Nikulov Alexey
Alexey Nikulov
Fundamental Differences Between Application of Basic Principles of Quantum Mechanics on Atomic and Higher Levels
3 pages, 1 figure, the talk was presented at the Eighth International Symposium Frontiers of Fundamental Physics, Madrid, October 17-19, 2006
in the AIP Conference Proceedings Vol. 905, p. 117 (2007)
10.1063/1.2736996
null
cond-mat.supr-con cond-mat.mes-hall
null
Superconductivity is macroscopic quantum phenomenon. From force of habit most physicists pay no heed to a paradoxicality of this fact. Niels Bohr considered quantum mechanics as atomic physics and the paradoxical quantum principles may be admissible on this level. But they seem quite strange on the macroscopic level. In the last years some experts, A. J. Leggett and other, attract our attention to a contradiction between quantum mechanics and macroscopic realism. In this paper I try to draw reader's attention to some paradoxical consequences of the Bohr quantization on the macroscopic level.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:39:05 GMT" } ]
2009-11-13T00:00:00
[ [ "Nikulov", "Alexey", "" ] ]
0707.0828
Xinjia Chen
Xinjia Chen, Kemin Zhou and Jorge L. Aravena
Probabilistic Robustness Analysis -- Risks, Complexity and Algorithms
28 pages, 5 figures
Published in SIAM Journal on Control and Optimization, vol. 47, pp. 2693--2723, 2008
null
null
stat.AP math.ST stat.TH
null
It is becoming increasingly apparent that probabilistic approaches can overcome conservatism and computational complexity of the classical worst-case deterministic framework and may lead to designs that are actually safer. In this paper we argue that a comprehensive probabilistic robustness analysis requires a detailed evaluation of the robustness function and we show that such evaluation can be performed with essentially any desired accuracy and confidence using algorithms with complexity linear in the dimension of the uncertainty space. Moreover, we show that the average memory requirements of such algorithms are absolutely bounded and well within the capabilities of today's computers. In addition to efficiency, our approach permits control over statistical sampling error and the error due to discretization of the uncertainty radius. For a specific level of tolerance of the discretization error, our techniques provide an efficiency improvement upon conventional methods which is inversely proportional to the accuracy level; i.e., our algorithms get better as the demands for accuracy increase.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:42:21 GMT" } ]
2008-11-01T00:00:00
[ [ "Chen", "Xinjia", "" ], [ "Zhou", "Kemin", "" ], [ "Aravena", "Jorge L.", "" ] ]
0707.0829
Jean-Francois Bony
Jean-Francois Bony
Mesures limites pour l'equation de Helmholtz dans le cas non captif
27 pages, 7 figures
null
null
null
math.AP math.FA
null
Cet article est consacre a l'etude des mesures limites associees a la solution de l'equation de Helmholtz avec un terme source se concentrant en un point. Le potentiel est suppose regulier et l'operateur non-captif. La solution de l'equation de Schrodinger semi-classique s'ecrit alors micro-localement comme somme finie de distributions lagrangiennes. Sous une hypothese geometrique, qui generalise l'hypothese du viriel, on en deduit que la mesure limite existe et qu'elle verifie des proprietes standard. Enfin, on donne un exemple d'operateur qui ne verifie pas l'hypothese geometrique et pour lequel la mesure limite n'est pas unique. Le cas de deux termes sources est aussi traite.
[ { "version": "v1", "created": "Thu, 5 Jul 2007 16:45:04 GMT" } ]
2007-07-06T00:00:00
[ [ "Bony", "Jean-Francois", "" ] ]