1 / 21

Search for low-energy semi-classical gravity effects

Search for low-energy semi-classical gravity effects. George E. A. Matsas Instituto de Física Teórica/ Unesp. Challenges of new physics in space for quantum gravity. Is the big bang a true singularity? What is the physics of super-hot universe: T> 10 19 GeV ?

kyleigh-dallaher
Download Presentation

Search for low-energy semi-classical gravity effects

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Search for low-energy semi-classical gravity effects George E. A. Matsas Instituto de Física Teórica/ Unesp

  2. Challengesofnewphysics in spacefor quantum gravity • Is the big bang a true singularity? • What is the physics of super-hot universe: T> 1019 GeV? • Is dark energy a (low-energy) quantum gravity effect? • Do black holes reallyevaporate? (transplanckian modes issue) • What is the final stage of black hole evaporation? • Is there any black hole information paradox? • Are there naked singularities and are they really “singular”? • Can quantum gravity fool the cosmic censor? • ...

  3. What is Quantum Gravity? NOBODY NOWS C. Rovelli, “Notes for a brief history of Quantum Gravity”, gr-qc/0006061

  4. Necessary condition: Quantum Gravity includes observables which depend simultaneously on c, h and G (in CGS units). Quantum gravity effect space Energy Full quantum gravity regime Semiclassical gravity regime Complexity (# of parameters)

  5. Full quantum gravity regime Semiclassical gravity regime Semiclassicalgravity (quantum fieldtheory in curvedspacetimes + backreactioneffects) Globally hiperbolic spacetimes

  6. Hawking effect (Nature 248(1974)30) Stanford Linear Accelerator Center cortesy Full quantum gravity regime Semiclassical gravity regime

  7. Unruh effect (Phys. Rev. D 14(1976)870) Crispino, GEAM, Higuchi, Rev.Mod.Phys. 80(2008)787 Stanford Linear Accelerator Center cortesy Full quantum gravity regime Semiclassical gravity regime Elementary particle concept D. Vanzella, GEAM, Phys.Rev.Lett. 87 (2001) 151301

  8. OldphysicsonEarthhelps newphysics in space Full quantum gravity regime Semiclassical gravity regime Hawking effect Unruh effect “Go slow to arrive the soonest”

  9. Sonicholes(Unruh, Phys. Rev. D 46(1981)1351) Full quantum gravity regime Problem: Transplanckian modes Solution(?): Is the spacetime like a fluid? Question: Do we loose Lorentz invariance at Planck scale? Semiclassical gravity regime hydrodynamics

  10. unpredictable ! CosmicCensorship Conjecture Full quantum gravity regime WeakCosmicCensorship Conjecture Ifone starts out withaninitiallynon-singularasymptotically flat situation, anysingularitieswhichsubsequentlydevelopdue to gravitationalcollapsewillbehiddenfromtheviewofanobserveratinfinitybytheeventhorizonof a blackhole (Penrose, Nuovo Cimento 1969) Semiclassical gravity regime Particle physics Naked singularities are so imoral that there may exist cosmic censors to dress them all (but the big bang) with event horizons.

  11. ANTI-Cosmic Censorship Conjecture ANTI-Cosmic Censorship Conjecture Because quantum gravity should unveil the physics of naked singularities and recover the predictability of the Universe, there must exist anti-cosmic censors guarantying the existence of naked-singularity quantum generation mechanisms Made predictable by quantum mechanics !

  12. time Nakedsingularityfrommattercollapse? Naked singularity SPECIAL initial conditions (Choptuik, PRL 1993)

  13. time Nakedsingularityfrommattercollapse? !? GENERIC initial conditions

  14. Black Holes and Naked Singularities Question: Is it possible to overspinorovercharge a blackholestripping bare a black hole to reveal its singularity?

  15. Throwing a classical particle into an extreme black hole particle particle Gravitational Potential For related work withfurtherdevelopmentssee “Overcharging a blackholeandcosmiccensorship”. (Hubeny, PRD 99) (Wald, Ann. Phys. 74)

  16. Overspinning a charged black hole via quantum tunneling? particle Gravitational Potential (G.E.A.M. & A.R.R. da Silva, Phys. Rev. Lett 2007) [comments also in Nature, 450, 147 (2007)]

  17. The backreaction issue (Hod, PRL 2008) (Richartz & Saa, PRD 2008) (GEAM, Richartz, Saa, da Silva, Vanzella, submitted to publication)

  18. Quantum Gravityfinal veredictum ?

  19. Generalized second law

  20. Naked singularity/elementary particle conjecture

  21. This is time to reflect on how risky our bets towards Quantum Gravity should be The End

More Related