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New exact solutions on the Randall-Sundrum 2-brane: lumps of dark radiation and accelerated black holes. Mohamed Anber HEP Bag Lunch April 1st With Lorenzo Sorbo. Outline. Higher dimensional spacetime: ADD, Randall-Sundrum models AdS/CFT
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New exact solutions on the Randall-Sundrum 2-brane: lumps of dark radiation and accelerated black holes Mohamed Anber HEP Bag Lunch April 1st With Lorenzo Sorbo
Outline • Higher dimensional spacetime: ADD, Randall-Sundrum models • AdS/CFT • Building black holes on branes (Emparan, Horwoitz and Myers construction) • New solutions on RS 2-Brane: Lump of radiation and accelerated black holes • AdS/CFT interpretation
Higher Dimensional Spacetime • Kaluza–Klein theory(1921): compactified extra dimensions, used extensively in unified field theories (string theory, M-theory ) • Large extra dimensions (ADD model-1998): Hierarchy problem (elevate it).
Randall-Sundrum model • Randall-Sundrum (I & II) models (1999): Hierarchy problem, SM lives on a brane in AdS space. • Model I: 2 branes
Randall-Sundrum model • Model II: single brane (the world lives on the Plank brane), the extra dimension is infinite but we have 4-D gravity on brane!! • String implementation for Add and RS models
AdS/CFT • Holography (Bekenstein, Susskind, ‘t Hooft, Bousso)
AdS/CFT • Maldacena conjecture (AdS/CFT) (1997) • Conformal=scale invariance, Roughly speaking
AdS/CFT Randall-Sundrum model provides a naturla set up to study AdS/CFT On the RS brane: gravity+CFT
AdS/CFT • Black holes localized on RS-branes: great opportunity to study BH evaporation (classical BH+CFT corrections) • This is important to shed some light on quantum gravity • But no localized BH on RS 3-brane (4+1 D spacetime) so far!! • Emparan, Horowitz and Myers (EHM) (1999) found BH on RS-2 brane (3+1 D)
EHM construction • First we need to understand gravity in 2+1 D • Gravity is not dynamical in 2+1 D • Vacuum Solution: conical singularity, no BH The same form of this metric in 4D describes a cosmic string
EHM construction • RS brane is accelerating in the AdS • If you want a BH on this brane, this BH should be accelerating as well in AdS • How to implement this picture?
EHM construction • Find some solution that describes an accelerating BH in AdS background: the AdS-C metric • Then cut it with an empty brane That is it!! String(conical singularity) Root H(y)
EHM construction • What we get? For flat brane (at x=0) • The conical singularity is dressed with a horizon . This horizon is quantum in nature (quantum cosmic censorship) • EHM also found that other solutions for non-flat branes (e.g. with AdS brane there is quantum corrected BTZ BH) • Are there any more allowed solutions? Yes!!
New Solutions M. Anber and L. Sorbo arXiv:0803.2242 • We want the most general brane embedding in the AdS-C metric. How to do it? • Take • Compute the extrinsic curvature • Write down Israel junction condition • We find K+ K-
New Solutions • But the AdS-C metric is invariant under the transformation • Then we also have • These are the only allowed solutions!! What is the physics of these new solutions?
New Solutions: Accelerated BHs on RS-2 brane • We take • The induced metric on this brane reads (after suitable parameter transformations)
In the bulk On the brane This metric describes accelerating BHs This is the first accelerating BH solution on a brane New Solutions: Accelerated BHs on RS-2 brane
New Solutions: Accelerated BHs on RS-2 brane • What is the CFT picture? Tr T=0 CFT Cosmological constant on brane
New Solutions: Accelerated BHs on RS-2 brane • This black hole is accelerating, there must be a string (adge on the brane) that can provide such acceleration
New Solutions: Accelerated BHs on RS-2 brane • F=mA+ O(mAG) Classical force Quantum effect
New Solutions: Lump of dark radiation • Now we take • To find the brane induced metric • With Friedman-like equation There is a conical singularity Cosmological constant Thermal radiation Hubble parameter curvature
New Solutions: Lump of dark radiation • The energy momentum tensor Cosmological constant radiation
New Solutions: Lump of dark radiation • This metric is very complicated • We study the limiting case with a flat barne • For m=0 we obtain • This is a flat metric! • The energy momentum tensor to first order of m
New Solutions: Lump of dark radiation Radiation density radius
New Solutions: Lump of dark radiation • This is a lump of radiation on top of conical geometry • No horizon, No quantum cosmic censorship! (this is time-dependent solution)
Conclusion • We have presented new solutions on RS-2 brane • We hope to learn something about the higher dimensional case • AdS/CFT is very exciting , recently many applications have been proposed: QCD plasma, superconductivity, etc.. • It would be great to see what applications one can find in the case of RS-2 brane