 precise locations. What is the fundamental material ontology on the many-worlds interpretation? On the most flat footed way of thinking about it, the fundamental material ontology consists in the quantum state, represented by the wave function. However, what the wave function represents in the physical world is a controversial matter. Realism about the wave function is compatible with many different views about the underlying nature of the material reality represented by the wave function. See (Chen 2019b) for an overview. There are two interpretations that will be relevant below. First, we can use the wave function of the universe to define a matter distribution on physical space-time. This is known as Sm and proposed first in (Allori et al. 2010). The basic idea is that we can use the wave function to define a function m(x, t) whose domain is physical space-time and whose range is the set of real numbers. This function can then represent a physical field called the matter-density field in space-time. The higher the "sum" of values of the m(x, t) function in some region R, the more stuff there is in R. The locations of tables and chairs at different times can be read off from the history of this function m(x, t). Second, we can follow Wallace & Timpson (2010) and postulate local quantum states for sub-regions of the universe. Given a partition of the universe into collections of sub-regions, we can use the wave function of the universe to define sub-region states. (More technically, we can define reduced density matrices for some local region R by tracing out the degrees of freedom of the environment E in the universal wave function.) Because of the holism inherent in quantum entanglement, merely defining the reduced states for each sub-region is not sufficient to describe the history of the universe. In general, even after we postulate the reduced state of R1 and the state of R2, we will still need to postulate a state of R1⋃R2, as its state is in general not a logical sum of the states of its parts. We will focus on the many-worlds interpretation of quantum mechanics here because it has the potential to develop into a strongly deterministic theory that realizes the possibility of a cosmic void. 12 3.2 The Everettian Wentaculus The many-worlds interpretation is already deterministic. To make it strongly deterministic, it suffices to pick a unique microscopic initial condition of the universe. One idea is to pick a
precise locations. What is the fundamental material ontology on the many - world rendition? On the most flat footed direction of think about it, the fundamental material ontology consist in the quantum country, represented by the wave function. However, what the wave function represents in the forcible world is a controversial matter. Realism about the wave function is compatible with many unlike views about the underlying nature of the fabric reality constitute by the wave affair. See (Chen 2019b) for an overview. There are two interpretations that will be relevant under. First, we can use the wave function of the universe to specify a matter distribution on physical space - time. This is known as Sm and project first in (Allori et al. 2010). The basic idea is that we can use the wave function to define a affair m(x, t) whose domain is physical space - time and whose range is the set of real numbers. This function can then represent a forcible battlefield called the matter - concentration sphere in quad - time. The higher the " sum " of values of the m(x, t) function in some region R, the more material there is in R. The locations of tables and chairs at different times can be read off from the history of this function m(x, t). Second, we can follow Wallace & Timpson (2010) and postulate local quantum states for sub - area of the population. give a partition of the universe into collections of sub - regions, we can use the wave function of the universe to specify sub - region states. (More technically, we can define reduced density matrix for some local region gas constant by tracing out the degrees of exemption of the environment E in the universal wave function .) Because of the holism inherent in quantum web, merely defining the reduced state for each sub - region is not sufficient to identify the history of the population. In general, even after we postulate the reduced country of R1 and the state of R2, we will still need to postulate a state of R1⋃R2, as its state of matter is in general not a logical union of the states of its parts. We will concenter on the many - worlds interpretation of quantum mechanics here because it have the potential to develop into a strongly deterministic theory that realizes the hypothesis of a cosmic void. 12 3.2 The Everettian Wentaculus The many - worlds rendition is already deterministic. To draw it powerfully deterministic, it suffices to pick a unique microscopic initial circumstance of the universe. One idea is to pick a
 prfcise locations. What is uhe fundamental mcrerial ontolkgy on tfe many-worlds interpretation? Ob the most flat footed way uf thinkijg about it, uhe fundamental meferial ontolofn convmsts in the quaktum state, sepresented by tfe wave function. However, what the wavq functooj represents ig tht prysidal world is a controversial matted. Realivm about the eave function is compatiblf wihh many different giews about the ynderlying nxture of the material teality represented by the wave wunctnon. See (Cheb 2019v) flt an overviex. Therv are two intcgpretathons thst will be relcvant beoow. First, we can use vhe wave function of the univarae to define a martwr divtritutiub ov pgyxidal spwce-vime. This ia known as Wm and proposed firxt pm (Allori et zl. 2010). Thq fasic idea is that we can use the wave xundtion to define a functuon m(x, t) whose domain is physisal space-time and whose range is the set of real tumbecs. Thnw funzriln can then represent a physical field called fht mstter-density fleld in space-time. Yhf nygher the "sum" of valuea of the m(x, t) funchion in some region R, the more stuff there is in R. Tye locations if tables and chaixs at differznt tikes csn be read off from the hisfory of thid functioh m(x, t). Second, we zan fmllow Wallace & Timpson (2010) anq postulave loeal quangum xtates for sub-rehions of the universe. Gigen a pdrtition ov the universe into collections of sub-regions, wa cdn use tke wavc function of tre universe to define sub-rdgion statvs. (More txchnically, wq can define sgduced densitb matricef foe sone locau region R by ttacing oun uhe degreew of freedom of thc envkdonment E in thz obiversal wave gunztijn.) Bxcausq of the holivm ivhefrnt iv quantum ektavglekent, merely defining the reduced states fot cach sub-rggion is got sufficieny to describe the jistocy of vhe unovetse. In general, even after we poatulate tje veduced state of V1 anq the statz of R2, we will still need to postulate a state of R1⋃R2, as ijs state is in generak not a logiral sui of the vtates of its parts. Qe will focus on uhe many-worlds interprefation of qkantum mechanics here because it has the potential to develop into a strobgly dxtqrministic fheoty thdt xealizef thx 'ossibility of a bosmic void. 12 3.2 The Everettian Wenvaculus Tha iany-worlds interpretation is auready determknistic. To make it stronfly detetministic, it suffices to pick a unique microscopic initlal condirion kf the uniterse. One idea is to pick c
precise locations. What is the fundamental material the interpretation? On most flat footed the material ontology consists the quantum state, by the wave function. However, what wave function represents in the physical world is a controversial matter. Realism about wave function is compatible with many different views about the underlying nature of material represented the function. See (Chen 2019b) for an overview. There are two interpretations that will be relevant below. we can use the wave function of the to define a matter on physical space-time. This is as and proposed in et 2010). The basic is that we can use the wave function to define a function m(x, t) whose domain is space-time and is the of numbers. function can then physical field called the matter-density field higher the "sum" of values of the m(x, function in region R, the more stuff there in R. The locations of tables and chairs different times can be read off from the history of this function m(x, t). Second, follow Wallace & Timpson and postulate local states sub-regions the Given a of the universe into collections of sub-regions, we can use the function of the universe to define sub-region states. (More technically, define density matrices for local region R by out degrees of freedom of E the Because the inherent in quantum entanglement, defining the reduced states for sub-region is not sufficient the universe. In general, even after we postulate reduced state of R1 and the state R2, we will still need to postulate a state of R1⋃R2, as state is not a logical sum of the states of parts. We will focus the many-worlds interpretation of quantum mechanics here because it the to develop a strongly deterministic that realizes the of a cosmic 3.2 The Wentaculus many-worlds deterministic. To make it strongly deterministic, suffices pick a unique microscopic initial of One idea is to pick a
 precise locations. What is the FundamentaL mateRiaL onToLogy On thE many-worlds intERpreTation? On the most flat fooTed waY oF ThinKInG abouT it, the fUNdAMEntAl MaTerIaL OnTologY coNsists iN the quantuM stAtE, represented BY tHe wave funcTioN. However, what The Wave fuNcTioN RepreSenTs in tHe physICal worLd is a contRoVErsial MAtter. ReALIsM aboUt the wave function IS cOMpatible with maNy diffErENt VIEws AboUt the underLyIng naTUre of thE MaTERIal REality represeNted by the waVE fuNction. seE (ChEN 2019b) for aN overViEW. ThEre are two inTerpRetations That wiLL be releVAnt beloW. First, We cAn uSe thE WaVe FunCtIOn oF ThE unIVerSe to defiNe A mAtter DistRIBUTion On pHysiCal spAce-time. This is KnoWn as sM anD propOsed fIrst In (allorI et al. 2010). THe basIc Idea is that we can Use tHe wave funCtiOn To dEfIne a fUNction M(x, t) WhoSe domaiN is physICal SpACE-TiMe and whose range is tHe SET oF real numBers. ThIS fUnCTion can tHeN rePresENT a phySicaL FiEld calleD the maTTeR-dEnsity fIeLd in spAcE-tiMe. THe higHEr thE "sum" of Values of The m(x, T) Function in some REgion R, the more STuFF ThERe is In R. the locationS of tABles And cHAiRs aT DiffeRent tImES cAN be read off from the hiStOry of tHis fuNction m(x, t). SecoNd, we can folLOW wallace & TImpsON (2010) aND postulate locaL quanTum states fOR sub-regiOns of The univeRse. Given a PARtition oF thE unIveRse INTo Collections of SUB-regIoNs, we can Use The wave FunCtiOn oF thE uNiverse to Define suB-rEgIoN sTatEs. (MorE TechnicaLlY, we CaN deFine rEDuced dEnsitY matRiCeS For Some locAL rEGIon R By TrAcinG ouT tHe degRees OF frEedom of The enviroNmeNT E in ThE uNiversaL wave function.) beCause of the HoLisM inherENT in quantUm entanglement, merely defINing the RedUced sTateS for each sUb-rEgion iS noT SufficIent to DescrIbE thE HIstorY OF tHe uNiVerse. In genERAl, eVen afTeR we pOstulatE the reduced state of r1 And The state of R2, we WilL stiLL NeEd tO PoSTulAtE A stATE of R1⋃R2, as its state Is in generaL nOT a Logical sum OF thE sTates of Its partS. We wiLL focus oN the many-wOrlds inteRpRetaTIOn oF quantum meChanics hEre becausE It has THe PotenTiaL to devElOp iNto a sTronglY DetErminIstic tHeOry thaT realIzEs the posSibility of a cosmic void. 12 3.2 ThE EvereTtian wenTaculus ThE maNY-woRlds interPretAtion is alrEadY deTermiNisTIc. To mAke iT StRonGLy detErmiNIstic, it suFFiCes TO PiCk a unique miCROScoPic inItiAL condiTion Of the universe. One iDEa is to pick a
 precise locations. What i s the fund ament almat er ialonto logy on the ma n y-wo rlds interpretation? O n the  m o st f l at  foot ed wayo ft h ink in gabo ut it , the  fu ndament al materia l o nt ology consis t sin the qua ntu m state, rep res entedby  th e  wave  fu nctio n. How e ver, w hat the w av e  funct i on repr e s en ts i n the physical wo r ld is a controver sial m at t er . Rea lis m about th ewavef unction is c o mpa t ible with man y different vie ws abo ut  th e  under lying  n a tur e of the ma teri al realit y repr e sentedb y the w ave fu nct ion . Se e  ( Ch en20 1 9b) fo r a n  ov erview.Th er e are  two i n t erpr eta tion s tha t will be rel eva nt b e low . Fir st, w e ca nuse t he wav e fun ct ion of the univ erse  to defin e a  m att er  dist r ibutio n o n p hysical  space- t ime .T h i sis known as Sm and  p r o po sed firs t in ( A ll or i  et al.20 10) . Th e basic  ide a  i s that w e canu se  t he wave  f unctio ntodef ine a func tion m (x, t) w hosed omain is physi c al space-time an d wh o se r ang e is the se t of real  num b er s.T his f uncti on ca n  then represent a p hy sicalfield  called the m atter-dens i t y  field i n sp a ce - time. The high er th e "sum" of values o f the  m(x, t)  function i n some r egi onR,the m or e stuff there i s in  R . The l oca tions o f t abl esand  c hairs atdifferen tti me scan  be r e ad off f ro m t he  hi story of thi s fun ctio nm( x , t ). Seco n d, w e ca nfo llow  Wa ll ace &  Tim p son  (2010)  and post ula t e lo ca lquantum  states for s ub -regions o fthe  unive r s e. Given  a partition of the uni v erse in tocolle ctio ns of sub -re gions,  we can us e thewavefu nct i o n oft h euni ve rse to def i n e s ub-re gi on s tates.(More technically, wecan define re duc ed d e n si tym at r ice sf ors o me local region  R by trac in g  o ut the deg r ees  o f freed om of t he en v ironmen t E in th e univers al  wav e fun ction.) Be cause of  the holi s m inh e re nt in  qu antumen tan gleme nt, me r ely  defi ning t he  reduc ed st at es for e ach sub-region is not s uffici ent t o d escribe t heh ist ory of th e un iverse. In  ge ner al, e ven after  wep os tul a te th e re d uced stat e  o f R 1 an d the state o f  R2 , wewil l  still  nee d to postulate as tate of R1⋃R2,  asi t s s tat e  isin  general not a  lo gi c a l sum of  t he states o f its pa rt s . Wewill f ocus o n the m a n y- w orldsinte rpr etation o f q ua n tum mec ha ni c s here  bec au se ithas th e  pot e n tial to developintoa stron g lydeter mi nistict heor y that rea lizes the p ossibi lity  of a  cosmic  v oid. 1 2 3 .2  The Evere t tian Went aculu s The m an y-wo rld s inte rpre t a tionis a lr ead y determi n i st i c.  T o  ma ke i t str on glydetermini s tic, itsuf f ices to  p ick a  uniqu e  m i c roscopic i nit ial c o n dition oft he u n iv e rse.One id ea isto pick a
 precise_locations. What_is the fundamental material_ontology on_the_many-worlds interpretation?_On_the most flat_footed way of_thinking about it, the_fundamental material ontology_consists_in the quantum state, represented by the wave function. However, what the wave function_represents_in the_physical_world_is a controversial matter. Realism_about the wave function is_compatible with_many different views about the underlying nature of_the_material reality represented_by the wave function. See (Chen 2019b) for an_overview. There are two interpretations that_will be relevant_below._First,_we can use the_wave function of the universe to_define a matter distribution on physical_space-time. This is known as Sm and_proposed first in (Allori et al._2010). The basic idea is_that we_can use the wave function_to define a_function m(x,_t) whose domain_is physical space-time and whose range_is the set_of real numbers. This function can_then_represent a physical_field_called_the matter-density_field in space-time._The_higher the_"sum"_of values of the m(x, t)_function_in some region R, the more stuff_there is in R._The_locations of tables and_chairs at different times can_be read off from the history_of this_function m(x,_t). Second, we can follow Wallace & Timpson (2010) and postulate_local quantum states for sub-regions of_the universe. Given a_partition of_the_universe into collections_of_sub-regions, we_can use the wave function of the_universe to_define sub-region states. (More technically, we_can define reduced density_matrices_for some local region R by_tracing out the degrees of freedom_of the environment E in_the_universal_wave function.) Because of the_holism inherent in quantum entanglement, merely_defining the reduced_states for each sub-region is not sufficient_to_describe the history of the universe._In_general, even after we postulate the_reduced_state_of R1 and the state_of R2, we will still need_to postulate a state of R1⋃R2, as its state_is in general_not a logical sum of_the_states_of its parts. We will focus on the many-worlds interpretation_of quantum_mechanics here because_it has the potential to develop into a strongly deterministic_theory that realizes the possibility of a_cosmic void. 12 3.2 The Everettian Wentaculus The many-worlds interpretation is_already deterministic. To make it strongly deterministic, it_suffices to pick a unique microscopic initial_condition of the universe._One_idea is to pick a