Albert-László Barabási
Albert-László Barabási (born March 30, 1967) is a Romanian-born Hungarian-American physicist, best known for his work in the research of network theory.

He is the former Emil T. Hofmann Professor at the University of Notre Dame and current Distinguished Professor and Director of Northeastern University's Center for Complex Network Research (CCNR) associate member of the Center of Cancer Systems Biology (CCSB) at the Dana–Farber Cancer Institute, Harvard University, and visiting professor at the Center for Network Science at Central European University.

He introduced in 1999 the concept of scale-free networks and proposed the Barabási–Albert model to explain their widespread emergence in natural, technological and social systems, from the cellular telephone to the World Wide Web or online communities. He is the Founding President of the Network Science Society, which grew out of and sponsors the flagship NetSci conference held yearly since 2006.

Birth and education
Barabási was born to an ethnic Hungarian family in Cârța, Harghita County, Romania. His father, László Barabási, was a historian, museum director and writer, while his mother, Katalin Keresztes, taught literature, and later became director of a children's theater. He attended a high school specializing in science and mathematics; in the tenth grade, he won a local physics olympiad. Between 1986 and 1989, he studied physics and engineering at the University of Bucharest; during that time, he began doing research on chaos theory, publishing three papers.

In 1989, Barabási emigrated to Hungary, together with his father. In 1991, he received a master's degree at Eötvös Loránd University in Budapest, under Tamás Vicsek, before enrolling in the Physics program at Boston University, where he earned a PhD in 1994. His thesis, written under the direction of H. Eugene Stanley, was titled Growth and roughening of non-equilibrium interfaces.

Academic career

After a one-year postdoc at the IBM Thomas J. Watson Research Center, Barabási joined the faculty at the University of Notre Dame in 1995. In 2000, at the age of 32, he was named the Emil T. Hofman Professor of Physics, becoming the youngest endowed professor. In 2004 he founded the Center for Complex Network Research.

In 2005–06 he was a Visiting Professor at Harvard University. In Fall, 2007, Barabási left Notre Dame to become the Distinguished Professor and Director of the Center for Network Science at Northeastern University and to take up an appointment in the Department of Medicine at Harvard Medical School.

As of 2008, Barabási holds Hungarian, Romanian and U.S. citizenship.

Research and achievements
Barabási has been a major contributor to the development of network science and the statistical physics of complex systems. His biggest role has been the independent rediscovery of the scale-free network concept. He reported the scale-free nature of the WWW in 1999 and the same year, in a Science paper with Réka Albert, he proposed the Barabási–Albert model, an undirected version of the Price model, predicting that growth and preferential attachment are jointly responsible for the emergence of the scale-free property in real networks. According to the review of one of Barabási's books, preferential attachment can be described as follows:"Barabási has found that the websites that form the network (of the WWW) have certain mathematical properties. The conditions for these properties to occur are threefold. The first is that the network has to be expanding, growing. This precondition of growth is very important as the idea of emergence comes with it. It is constantly evolving and adapting. That condition exists markedly with the world wide web. The second is the condition of preferential attachment, that is, nodes (websites) will wish to link themselves to hubs (websites) with the most connections. The third condition is what is termed competitive fitness which in network terms means its rate of attraction."

He subsequently showed that the scale-free property emerges in biological systems, namely in metabolic networks and protein–protein interaction networks. In a 2001 paper with Réka Albert and Hawoong Jeong he demonstrated the Achilles' heel property of scale-free networks, showing that such networks are robust to random failures but fragile to attacks. The implications of this robustness and fragility also extend to many infrastructure systems, though it has been argued that the internet's resilience is not related to the scale-free structure. Some have pushed back on whether power-laws are as ubiquitous as suggested and noted that power-laws with exponential cutoffs or lognormal distributions might be better descriptors of many real datasets. Following this debate, Serafino et al. used a finite size scaling analysis to reaffirm the universality of power-laws over a large ensemble of real-world networks.  

Barabási's contributions to network biology and network medicine include introducing the concept of diseasome, or disease network, showing how diseases link to each other through shared genes and pioneered the use of large patient data to explore disease comorbidity, linking it to molecular network data. Nicholas Bray and Lior Pachter criticized some of Barabási's work in computational biology in a blog post, attacking the entire field of network science as part of a series against several leading researchers.

His work on human dynamics resulted in the discovery of the fat tailed nature of the inter event times in human activity patterns, and proposed the Barabási model that showed that a queuing model was capable of explaining the bursty nature of human activity. This topic is covered by his book Bursts.

His work on network control and observability brought the tools of control theory to network science. It asked how to identify the nodes from which one can control a complex network, just like a car is controlled through three control points, the steering wheel, gas pedal and the brake. By establishing an exact mapping between the dynamical control problem and matching theory, he developed tools to identify the system's control nodes. The same mapping allowed the determination of observers, nodes whose state allows one to reconstruct the state of the full system. Further work noted that nodal dynamics, which were not considered in the original contribution, also play a crucial role in network control.

Awards
He was elected a  Fellow of the American Physical Society in 2003. In 2005, he was awarded the FEBS Anniversary Prize for Systems Biology and in 2006 he was awarded the John von Neumann Medal by the John von Neumann Computer Society from Hungary, for outstanding achievements in computer-related science and technology.

In 2004, he was elected as an external member of the Hungarian Academy of Sciences. In 2007, he was inducted into the Academia Europaea.

In 2008 he received the 2008 C&C Prize, Japan "for stimulating innovative research on networks and discovering that the scale-free property is a common feature of various real-world complex networks" and the Cozzarelli Prize, National Academies of Sciences (USA)

The Lagrange Prize-Crt Foundation was awarded to Barabási in June 2011, and in November 2011 he was awarded Honorary degree Doctor Honoris Causa by Technical University of Madrid. In 2017 he received the Senior scientific award of the Complex Systems Society for  "setting the basis of what is now modern Network Science". In 2018 Barabási has received an honorary doctorate from Utrecht University at the occasion of her 382th Dies Natalis.

In June 2018 he was elected member of the Romanian Academy of Sciences. 

The Bolyai Prize was awarded to Mr. Barabási in May 2019 by the Hungarian Academy of Sciences, handed over by the President of Hungary, János Áder.

Selected publications
 Barabási, Albert-László, The Formula: The Universal Laws of Success, November 6, 2018;  (hardcover)

 Barabási, Albert-László, Bursts: The Hidden Pattern Behind Everything We Do, April 29, 2010;  (hardcover)
 Barabási, Albert-László, Linked: The New Science of Networks, 2002.  (pbk)
 Barabási, Albert-László and Réka Albert, "Emergence of scaling in random networks", Science, 286:509–512, October 15, 1999
 Barabási, Albert-László and Zoltán Oltvai, "Network Biology", Nature Reviews Genetics 5, 101–113 (2004)
 Barabási, Albert-László, Mark Newman and Duncan J. Watts, The Structure and Dynamics of Networks, 2006; 
 Barabási, Albert-László, Natali Gulbahce, and Joseph Loscalzo, "Network Medicine", Nature Reviews Genetics 12, 56–68 (2011)
 
Y.-Y. Liu, J.-J. Slotine, A.-L. Barabási, "Controllability of complex networks", Nature 473, 167–173 (2011)
Y.-Y. Liu, J.-J. Slotine, A.-L. Barabási, "Observability of complex systems", Proceedings of the National Academy of Sciences 110, 1–6 (2013)
Baruch Barzel and A.-L. Barabási, "Universality in Network Dynamics", Nature Physics 9, 673–681 (2013)
Baruch Barzel and A.-L. Barabási, "Network link prediction by global silencing of indirect correlations", Nature Biotechnology 31, 720–725 (2013)
B. Barzel Y.-Y. Liu and A.-L. Barabási, "Constructing minimal models for complex system dynamics", Nature Communications 6, 7186 (2015)

References

External links
Albert-László Barabási professional website
Research Publications
Profile, Center for Complex Network Research 
Profile, Northeastern University website
Profile , Center for Cancer Systems Biology (CCSB) website
Profile, University of Notre Dame website

1967 births
Living people
American people of Hungarian-Romanian descent
21st-century American physicists
Romanian physicists
Members of the Hungarian Academy of Sciences
Complex systems scientists
Northeastern University faculty
University of Notre Dame faculty
Boston University alumni
University of Bucharest alumni
Romanian people of Hungarian descent
People from Harghita County
Members of Academia Europaea
Probability theorists
Harvard Medical School faculty
Fellows of the American Physical Society
Network scientists