Related papers: On Gauge Bosons in the Matrix Model Approach to M …
In particle physics model building discrete symmetries are often invoked to forbid unwanted or dangerous couplings. A classical example is the R-parity of the MSSM, which guarantees the absence of dimension four baryon- and lepton-number…
Using a reformulation of the method of (p,q) webs, we study the four-dimensional N=1 quiver theories from M-theory on seven-dimensional manifolds with G_2 holonomy. We first construct such manifolds as U(1) quotients of eight-dimensional…
The low-energy supersymmetric quantum mechanics describing D-particles in the background of D8-branes and orientifold planes is analyzed in detail, including a careful discussion of Gauss' law and normal ordering of operators. This…
The heterotic $E_8\times E_8$ string compactified on an orbifold $T^4/\IZ_N$ has gauge group $G\times G'$ with (massless) states in its twisted sectors which are charged under both gauge group factors. In the dual M-theory on…
We study the symmetry structure of N=8 quantum mechanics, and apply it to the physics of D0-brane probes in type I' string theory. We focus on the theory with a global $Spin(8)$ R symmetry which arises upon dimensional reduction from $2d$…
The D0-brane/Banks-Fischler-Shenker-Susskind matrix theory is a strongly coupled quantum system with an interesting gravity dual. We develop a scheme to derive bootstrap bounds on simple correlators in the matrix theory at infinite $N$ at…
We present brane constructions in Type IIA string theory for N=1 supersymmetric SO and Sp gauge theories with tensor representations using an orientifold 6-plane. One limit of these set-ups corresponds to N=2 theories previously constructed…
For five-dimensional braneworlds with an $S_1/\mathbb{Z}_2$ orbifold topology for the extra dimension $x^5$, we discuss the validity of recent claims that a gauge exists where the two boundary branes lie at fixed positions and the metric…
Duality between the E_8 x E_8 heterotic string and Type I' theory predicts a tower of D(irichlet)-particle bound states corresponding to perturbative heterotic string states. In the limit of infinite Type I' coupling, some of these bound…
Based on recent developments, in this letter we find 2+1 dimensional gauge theories with scale invariance and N=8 supersymmetry. The gauge theories are defined by a Lagrangian and are based on an infinite set of 3-algebras, constructed as…
We study a non-supersymmetric $E_8\times\bar E_8$ compactification of M-theory on $S^1/Z_2$, related to the supersymmetric $E_8\times E_8$ theory by a chirality flip at one of the boundaries. This system represents an M-theory analog of the…
We have examined the localization of gauge bosons on the three-brane embedded in 5D bulk space-time, and we find two kinds of branes on which both graviton and gauge bosons can be trapped. One is the dS brane with a positive cosmological…
We discuss issues related to orientifolds and the brane realization for gauge theories with orthogonal and symplectic groups. We specifically discuss the case of theories with (hidden) global SO(2n) symmetry, from three to six dimensions.…
We study a bound state of fractional D3/D7-branes in the ten-dimensional space R^{1,5}*R^{4}/Z_2 using the boundary state formalism. We construct the boundary actions for this system and show that higher order terms in the twisted fields…
Using boundary states we derive the presence of (chiral) fermions on the intersection of type 0 D-branes. The corresponding anomalous couplings on the branes are then computed. Furthermore, we discuss systems of branes sitting at $A_n$…
By fibering the duality between the $E_{8}\times E_{8}$ heterotic string on $T^{3}$ and M-theory on K3, we study heterotic duals of M-theory compactified on $G_{2}$ orbifolds of the form $T^{7}/\mathbb{Z}_{2}^{3}$. While the heterotic…
Gauge theory approach to consideration of the Nambu-Goldstone bosons as gauge and vector fields represented by the Cartan forms of spontaneously broken symmetries, is discussed. The approach is generalized to describe the fundamental branes…
In a recent paper, Polchinski and Strassler found a string theory dual of a gauge theory with reduced supersymmetry. Motivated by their approach, we perturb the $\N=8$ theory living on a set of N M2 branes to $\N=2$, by adding fermion mass…
T-branes, which are non-Abelian bound states of branes, were first introduced by Cecotti, Cordova, Heckman and Vafa \cite{Cecotti:2010bp}. They are the refined version of the monodromic branes that feature in the phenomenological F-theory…
We consider heterotic string theories in nine and eight dimensions. We identify the disconnected part of the spacetime gauge group by studying the outer automorphism of the charge lattices. The absence of the global symmetry indicates the…