8 papers · 1 filter
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…
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 $α'…
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…
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…