16 citations · 62 across the 17 of their papers we have counts for
17 papers
de Sitter in String Theory vs. Gibbons & Hawking
Yoav Zigdon
This paper corroborates a statement that perturbative string theory does not admit a solution whose spacetime metric is de Sitter times a closed manifold, to all orders in the …
Bridging Worldsheet CFTs and Wormholes
Yoav Zigdon
I provide multiple examples of conformal field theories (CFTs) on the worldsheet that describe string propagation in target space wormholes connecting two disjoint asymptotic manif…
Superball of Strings
Yoav Zigdon
I solve the equations of the low-energy limit of string theory to obtain a solution corresponding to a microcanonical ensemble of highly-excited superstrings. This ``Superball of S…
BPS Fivebrane Stars and BTZ Black Holes
Emil J. Martinec, Yoav Zigdon
We construct a large new class of BPS supergravity solutions parametrized by arbitrary chiral wave profiles on fundamental string and Neveu-Schwarz fivebrane sources. The effective…
A Charge Constraint in BMN
Yoav Zigdon
I derive a new charge constraint in -BPS sectors of the Berenstein, Maldacena, and Nastase (BMN) supersymmetric, gauged matrix quantum mechanics. It was previo…
BPS Fivebrane Stars III: Effective Actions
Emil J. Martinec, Yoav Zigdon
An effective action for NS5-branes coupled to supergravity is used to derive the full 10d form of horizon-free BPS solutions of fivebranes carrying momentum waves, including both t…
Stringy Forces in the Black Hole Interior
Yoav Zigdon
Effective field theories break down inside large black holes on macroscopic scales when tidal forces are string-sized. If is the horizon radius and is the square of the…
Self Gravitating Spinning String Condensates
Jorge E. Santos, Yoav Zigdon
In the context of the black hole/string transition, it is useful to produce Euclidean string backgrounds representing hot and self-gravitating strings. We utilise analytical and nu…
BPS Fivebrane Stars II: Fluctuations
Emil J. Martinec, Yoav Zigdon
We investigate quantum fluctuations of metric components in coherent 1/2-BPS bound states of fundamental strings and NS5-branes. The leading order contribution in an ex…
BPS Fivebrane Stars I: Expectation Values of Observables
Emil J. Martinec, Yoav Zigdon
We study ensembles of 1/2-BPS bound states of fundamental strings and NS-fivebranes (NS5-F1 states) in the AdS decoupling limit. We revisit a solution corresponding to an ensemble…
On the Entropy of Strings and Branes
Ram Brustein, Yoav Zigdon
We show that the entropy of strings that wind around the Euclidean time circle is proportional to the Noether charge associated with translations along the T-dual time direction. W…
Thermal Equilibrium in String Theory in the Hagedorn Phase
Ram Brustein, Yoav Zigdon
In string theory, a thermal state is described by compactifying Euclidean time on a thermal circle , of fixed circumference. However, this circumference is a dynamical fie…
A Puncture in the Euclidean Black Hole
Ram Brustein, Amit Giveon, Nissan Itzhaki +1
We consider the backreaction of the winding condensate on the cigar background. We focus on the case of the cigar associated with, e.g., the near-horizon…
Black Hole Entropy Sourced by String Winding Condensate
Ram Brustein, Yoav Zigdon
We calculate the entropy of an asymptotically Schwarzschild black hole (BH), using an effective field theory of winding modes in type II string theory. In Euclidean signature, the…
Effective field theory for closed strings near the Hagedorn temperature
Ram Brustein, Yoav Zigdon
We discuss interacting, closed, bosonic and superstrings in thermal equilibrium at temperatures close to the Hagedorn temperature in flat space. We calculate S-matrix elements of t…
Revealing the interior of black holes out of equilibrium in the SYK model
Ram Brustein, Yoav Zigdon
The Sachdev-Ye-Kitaev (SYK) model can be used to describe black holes (BHs) in two-dimensional nearly-anti-de-Sitter gravity. We show that when such BHs are perturbed by a time-dep…
The state of Hawking radiation is non-classical
Ram Brustein, A. J. M. Medved, Yoav Zigdon
We show that the state of the Hawking radiation emitted from a large Schwarzschild black hole (BH) deviates significantly from a classical state, in spite of its apparent thermal n…