Density of States, Black Holes and the Emergent String Conjecture
by
Max Wiesner(Harvard University)
→
Europe/Berlin
online
online
Description
In this talk I will discuss universal features of the density of one-particle states in weakly coupled theories of gravity, at energies above the quantum gravity cutoff. Using thermodynamic properties of black holes, I will show that in asymptotically flat spacetimes certain features of the density of states above the black hole threshold are an indicator for the existence of large extra dimensions that cannot be reproduced by any lower-dimensional field theory that satisfies the weak energy condition. Based on the properties of gravitational scattering amplitudes, I will argue that there needs to exist a (possibly higher-dimensional) effective description of gravity valid up to the cutoff. Combining this with thermodynamic arguments we demonstrate that the density of one-particle states has to grow exponentially for energies between QG cutoff and black hole threshold. Based on this I will further argue that in gravitational weak-coupling limits the lightest tower of states is either a KK tower, or has an exponentially growing degeneracy thereby resembling a string tower. This provides evidence for the Emergent String Conjecture without explicitly relying on string theory or supersymmetry. This talk is based on work to appear in collaboration with Alek Bedroya and Rashmish K. Mishra.
