相关论文: NC Geometry and Fractional Branes

We consider M-theory in the presence of M parallel M5-branes probing a transverse A_{N-1} singularity. This leads to a superconformal theory with (1,0) supersymmetry in six dimensions. We compute the supersymmetric partition function of…

In the space of couplings of the 4D N=1 gauge theory associated to D3 branes probing Calabi-Yau singularities, there is a manifold over which superconformal invariance is preserved. The AdS/CFT correspondence is valid precisely for this…

Using a ``Superstrings with Torsion'' type description, we study a class of IIB orientifolds in which spacefilling O5 planes and D5 branes wrap the T^2 fiber in a warped modification of the product of 4D Minkowski space and a T^2 fibration.…

We present a prescription in F-theory for realizing matter in "exotic" representations of product gauge groups. For 6D vacua, bifundamental hypermultiplets are engineered by starting at a singular point in moduli space which includes 6D…

We introduce unsupervised machine learning techniques in order to identify toric phases of 4d N=1 supersymmetric gauge theories corresponding to the same toric Calabi-Yau 3-fold. These 4d N=1 supersymmetric gauge theories are worldvolume…

Boundary states for D-branes at orbifold fixed points are constructed in close analogy with Cardy's derivation of consistent boundary states in RCFT. Comments are made on the interpretation of the various coefficients in the explicit…

We study topological strings on non-commutative resolutions of singular Calabi-Yau threefolds that are double covers of $\mathbb{P}^3$, ramified over determinantal octic surfaces. Using conifold transitions to complete intersections in…

A popular way to study N=1 supersymmetric gauge theories is to realize them geometrically in string theory, as suspended brane constructions, D-branes wrapping cycles in Calabi-Yau manifolds, orbifolds, and otherwise. Among the applications…

We give an elementary introduction to the recent derivation of the effective low-energy gauge theories of D3-branes probing orientifolds of toric Calabi-Yau 3-fold singularities via brane tiling techniques.

Conifold geometries have recieved a lot of attention in string theory and string-inspired cosmology recently, in particular the Klebanov-Strassler background that is known as the "warped throat". It is our intention in this article to give…

We solve $\mathcal{N}=1$ supersymmetric $A_{2}$ type $U(N)\times U(N)$ matrix models obtained by deforming $\mathcal{N}=2$ with symmetric tree level superpotentials of any degree exactly in the planar limit. These theories can be…

We consider quotients of string and M-theory by discrete subgroups of the U-duality group. This results in what we call O-folds, which are generalisations of orbifolds and orientifolds, and generically involve non-geometric identifications…

We use toric geometry to study open string mirror symmetry on compact Calabi-Yau manifolds. For a mirror pair of toric branes on a mirror pair of toric hypersurfaces we derive a canonical hypergeometric system of differential equations,…

We discuss chiral supersymmetric compactifications of the SO(32) heterotic string on Calabi-Yau manifolds equipped with direct sums of stable bundles with structure group U(n). In addition we allow for non-perturbative heterotic…

Brane tilings are efficient mnemonics for Lagrangians of N=2 Chern-Simons-matter theories. Such theories are conjectured to arise on M2-branes probing singular toric Calabi-Yau fourfolds. In this paper, a simple modification of the…

We investigate four-dimensional N=1 Type IIB orientifolds with continuous Wilson lines, and their T-dual realizations as orientifolds with moving branes. When continuous Wilson lines become discrete the gauge symmetry is enhanced and the…

This thesis contains an introductory chapter on orbifolds. The following chapter explains the foundations of orientifolds. Chapters 4-7 present own research. In chapter 4 we quantize open strings with linear boundary conditions, as they…

Discrete gauge symmetries in global intersecting D-brane models constrain the exact form of the perturbative as well as non-perturbative superpotential. We derive the complete set of conditions on the existence of discrete Zn gauge…

Starting with configurations of fourbranes, fivebranes, sixbranes and orientifolds in Type IIA string theory we derive via M-theory the curves solving N=2 supersymmetric gauge theories with gauge groups SO(N) and Sp(2N). We also obtain new…

We study the dynamics of M-theory on isolated non-toric Calabi-Yau threefold singularities of type $(A_j,A_l)$ and $(A_k,D_n)$, engineering five-dimensional rank-zero SCFTs. Our approach consists in mapping these backgrounds to type IIA…