Analogue cosmology in relativistic fluids

doctoral thesis

• Title: Analogna kozmologija u relativističkim fluidima
• Author: Dijana Tolić
• Mentor: Nevenko Bilić (mentor)
• Committee member: Nevenko Bilić (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2015-05-20, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics
• Universal decimal classification (UDC): 53; NATURAL SCIENCES; Physics

Abstract

Glavni ciljevi ove disertacije su postići vjerno simuliranje širenja svemira pomoću analognih modela gravitacije i istražiti doprinos analogne kozmološke produkcije čestica u relativističkom hadronskom fluidu. Koristeći ideju da je zakrivljenost u geometriji prostora moguće postići dinamikom fluida, opisani su učinci klasične gravitacije u analognom relativističkom sustavu. Dan je teorijski recept kako u realističnom laboratoriju visokih energija reproducirati gravitacijske fenomene koje nije moguće direktno opaziti u prirodi, kao što su Hawkingovo zračenje, vremenski ovisne konfiguracije crnih rupa i dinamika evolucije širećeg svemira. Geometrija i evolucija analognog prostor-vremena određene su jednadžbama mehanike fluida, za razliku od opće teorije relativnosti gdje ovu ulogu igraju Einsteinove jednadžbe. Kao prirodni medij za relativističke analogne modele proučavamo hadronsku materiju nastalu u sudarima teških iona. Ekstremni uvjeti visoke gustoće i temperature u kojima nastaje hadronska materija odgovaraju uvjetima u ranom svemiru neposredno nakon Velikog Praska. Pokazuje se kako propagacija bezmasenih piona u hadronskom fluidu simulira analogni svemir geometrijski ekvivalentan Friedmann-Robertson-Walkerovom (FRW) prostor-vremenu s negativnom prostornom zakrivljenošću. Dobiveni su uvjeti pod kojima se u hadronskom fluidu formiraju uhvaćene plohe te je izračunata temperatura analognog Hawkingovog zračenja iz uhvaćenog horizonta. Napravljena je kvantitativna usporedba analogne kozmološke produkcije čestica i analognog Hawkingovog zračenja.

Abstract (english)

The main objectives of this research are to faithfully simulate the expansion of the universe using analog models of gravity and investigate the contribution of the analog cosmological particle production in a relativistic hadronic fluid. Using the idea that a curved space geometry can be achieved by the means of fluid dynamics, the effects of classical gravity in relativistic analog system are described. A theoretical recipe is given how to reproduce, in a high-energy realistic laboratory, gravitational phenomena that can not be directly observed in nature, such as the Hawking radiation, time-dependent configurations of black holes and evolution dynamics of an expanding universe. Geometry and evolution of analog spacetime are determined by the equations of fluid mechanics, in contrast to the general relativity where they are described by Einstein’s equations. As a natural medium for relativistic analog models we study the hadron matter created in relativistic heavy ion collisions. Extreme conditions of very high density and temperature in which hadronic matter is created correspond to the conditions in the early universe shortly after the Big Bang. It is shown that propagation of massles pions in the hadronic fluid simulates an analog universe which is geometrically equivalent to the Friedmann-Robertson- Walker (FRW) spacetime with negative spatial curvature. We find the conditions under which trapped surfaces are formed and calculate the analog Hawking radiation temperature from the trapped horizon. A quantitative comparison of analogue cosmological particle production and analogue Hawking radiation is given.

• Keywords: analogna gravitacija; FRW svemir; Hawkingov učinak; uhvaćeni horizont; kozmološka produkcija čestica
• Keywords (english): analog gravity; FRW universe; Hawking effect; trapped horizon; cosmological particle production
• Language: croatian
• URN:NBN: urn:nbn:hr:217:650134
• Study programme: Title: Fizika; Study programme type: sveučilišni; Study level: poslijediplomski doktorski; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje fizika (doktor/doktorica znanosti, područje prirodnih znanosti, polje fizika)
• Type of resource: Text
• Extent: 89 str.
• File origin: Born digital
• Access conditions: Restricted access
• Created on: 2017-08-22 09:48:20