Geometric Aspects of D-branes and T-duality (2009)
Becker, Katrin, Bergman, Aaron
We explore the differential geometry of T-duality and D-branes. Because D-branes and RR-fields are properly described via K-theory, we discuss the (differential) K-theoretic generalization of...
New Boundaries for the B-Model (2008)
Witten couples the open topological B-model to a holomorphic vector bundle by adding to the boundary of the worldsheet a Wilson loop for an integrable connection on the bundle. Using the descent...
A Note on Support in Triangulated Categories (2008)
In this note, I define a notion of a compactly supported object in a triangulated category. I prove a number of propositions relating this to traditional notions of support and give an application to...
Ramond-Ramond Fields, Cohomology and Non-Geometric Fluxes (2007)
Bergman, Aaron, Robbins, Daniel
We consider compactifications of type II string theory in which a d-dimensional torus is fibered over a base X. In string theory, the transition functions of this fibration need not be simply...
Wormholes in Maximal Supergravity (2007)
Bergman, Aaron, Distler, Jacques
In this brief note, we reconsider the problem of finding Euclidean wormhole solutions to maximal supergravity in d dimensions. We find that such solutions exists for all d less than or equal to 9....
Stability Conditions and Branes at Singularities (2007)
I use Bridgeland's definition of a stability condition on a triangulated category to investigate the stability of D-branes on Calabi-Yau cones given by the canonical line bundle over a del Pezzo...
Deformations and D-branes (2006)
I discuss the relation of Hochschild cohomology to the physical states in the closed topological string. This allows a notion of deformation intrinsic to the derived category. I use this to identify...
Moduli spaces for Bondal quivers (2005)
Bergman, Aaron, Proudfoot, Nicholas J.
Given a sufficiently nice collection of sheaves on an algebraic variety V, Bondal explained how to build a quiver Q along with an ideal of relations in the path algebra of Q such that the derived...
Moduli Spaces for D-branes at the Tip of a Cone (2005)
Bergman, Aaron, Proudfoot, Nicholas J.
For physicists: We show that the quiver gauge theory derived from a Calabi-Yau cone via an exceptional collection of line bundles on the base has the original cone as a component of its classical...
Undoing Orbifold Quivers (2005)
A number of new papers have greatly elucidated the derivation of quiver gauge theories from D-branes at a singularity. A complete story has now been developed for the total space of the canonical...
Loop Groups, Kaluza-Klein Reduction and M-Theory (2004)
Bergman, Aaron, Varadarajan, Uday
We show that the data of a principal G-bundle over a principal circle bundle is equivalent to that of a \hat{LG} = U(1) |x LG bundle over the base of the circle bundle. We apply this to the...
1+1 Dimensional Critical String Theory and Holography (2003)
Bergman, Aaron, Distler, Jacques, Varadarajan, Uday
In hep-th/0310120, Goheer, Kleban and Susskind argued that the holographic principle is inconsistent with the existence of stable, Lorentz invariant, 1+1 dimensional compactifications. We note some...
The Volume of some Non-spherical Horizons and the AdS/CFT Correspondence (2001)
Bergman, Aaron, Herzog, Christopher P.
We calculate the volumes of a large class of Einstein manifolds, namely Sasaki-Einstein manifolds which are the bases of Ricci-flat affine cones described by polynomial embedding relations in C^n....
Nonlocal Field Theories and their Gravity Duals (2001)
Bergman, Aaron, Dasgupta, Keshav, Ganor, Ori J., Karczmarek, Joanna L., Rajesh, Govindan
The gravity duals of nonlocal field theories in the large N limit exhibit a novel behavior near the boundary. To explore this, we present and study the duals of dipole theories - a particular class...
A Note on Intersecting and Fluctuating Solitons in 4D Noncommutative Field Theory (2001)
Bergman, Aaron, Ganor, Ori J., Karczmarek, Joanna L.
We examine the intersections, fluctuations and deformations of codimension two solitons in field theory on noncommutative $R^4$, in the limit of large noncommutativity. We find that holomorphic...
Dipoles, Twists and Noncommutative Gauge Theory (2000)
T-duality of gauge theories on a noncommutative $T^d$ can be extended to include fields with twisted boundary conditions. The resulting T-dual theories contain novel nonlocal fields. These fields...