相关论文: Spin(7) Orientifolds and 2d $\mathcal{N}= (0,1)$ T…
The mechanics of an oriented point (point with "spin") based on 3D and 4D Frenet equations is considered. In such mechanics there is an opportunity to describe formally any physical trajectory of a particle with own rotation. We use…
The web of dual gauge theories engineered from a class of toric Calabi-Yau threefolds is explored. In previous work, we have argued for a triality structure by compiling evidence for the fact that every such manifold $X_{N,M}$ (for given…
We consider unoriented strings in the supersymmetric SL(2,R)/U(1) coset, which describes the two-dimensional Euclidean black hole, and its mirror dual N=2 Liouville theory. We analyze the orientifolds of these theories from several…
In the context of holography, we analyse aspects of supersymmetric geometries based on two-dimensional orbifolds known as spindles. By analysing spin$^c$ spinors on a spindle with an azimuthal rotation symmetry we show that under rather…
We consider string perturbative expansion in the presence of D-branes imbedded in orbifolded space-time. In the regime where the string coupling is weak and $\alpha'\to 0$, the string perturbative expansion coincides with `t Hooft's large N…
The complete D-brane spectrum in $\Zop_2$ orientifolds is computed. Stable non-BPS D-branes with both integral and torsion charges are found. The relation to K-theory is discussed and a new K-theory relevant to orientifolds is suggested.
The cancellation of U(1)-gauge and U(1)-gravitational anomalies in certain D=4 N=1 Type IIB orientifolds is analyzed in detail, from a string theory point of view. We verify the proposal that these anomalies are cancelled by a Green-Schwarz…
Horava--Witten M theory -- heterotic string duality poses special problems for the twisted sectors of heterotic orbifolds. In [1] we explained how in M theory the twisted states couple to gauge fields apparently living on M9 branes at both…
We discuss the lift of certain D6-antiD6-brane systems to M-theory. These are purely gravitational configurations with a bolt singularity. When reduced along a trivial circle, and for large bolt radius, the bolt is related to a…
Recently it has been shown that D-branes in orientifolds are not always described by equivariant Real K-theory. In this paper we define a previously unstudied twisted version of equivariant Real K-theory which gives the D-brane spectrum for…
A construction of compact tachyon-free orientifolds of the non-supersymmetric Type 0B string theory is presented. Moreover, we study effective non-supersymmetric gauge theories arising on self-dual D3-branes in Type 0B orbifolds and…
We investigate the classical geometry corresponding to a collection of fractional D3 branes in the orbifold limit of an ALE space. We discuss its interpretation in terms of the world-volume gauge theory on the branes, which is in general a…
We investigate D-branes in orientifolds of WZW models. A connection between the conformal field theory approach to orientifolds and the target space motivated analysis is established. In particular, we associate previously constructed…
We study the O3-plane in the conifold. On the D3-brane world-volume we obtain SO x USp gauge theory that exhibits a duality cascade phenomenon. The orientifold projection is determined on the type IIB string side, and corresponds to that of…
We describe orientifold operation defining O3 plane in the conifold background by deriving it from that of O4 plane in the Type IIA brane construction by T-duality. We find that both $O3^+$ and $O3^-$ are at the tip of the cone so that…
We classify 5d N=1 gauge theories carrying a simple gauge group that can arise by mass-deforming 5d SCFTs and 6d SCFTs (compactified on a circle, possibly with a twist). For theories having a 6d UV completion, we determine the tensor branch…
We study dimensional reductions of M-theory/type II strings down to 6D in the presence of fluxes and spacetime filling branes and orientifold planes of different types. We classify all inequivalent orientifold projections giving rise to…
We study a class of four-dimensional N=1 superconformal field theories obtained from the six-dimensional (1,0) theory, on M5-branes on C^2/Z_k orbifold singularity, compactified on a Riemann surface. This produces various quiver gauge…
We study the weak gravity conjecture, the swampland distance conjecture and the emergence proposal for $\mathcal{N}=1$ orientifold compactifications of type IIB string theory with O3-/O7-planes. We allow for orientifold projections with…
We study the orientifold of the ${\mathcal{N}} = 1$ superconformal field theories describing D3-branes probing the Suspended Pinch Point singularity, as well as the orientifolds of non-chiral theories obtained by a specific orbifold…