Showing papers by "Micha Berkooz published in 1999"

IR Dynamics of d=2, N=(4,4) Gauge Theories and DLCQ of "Little String Theories"

Abstract: We analyze the superconformal theories (SCFTs) which arise in the low-energy limit of N=(4,4) supersymmetric gauge theories in two dimensions, primarily the Higgs branch SCFT. By a direct field theory analysis we find a continuum of "throat"-like states localized near the singularities of the Higgs branch. The "throat" is similar to the "throat" found in the Coulomb branch of the same theories, but the full superconformal field theories of the two branches are different. A particular example is the SCFT of the R^4/Z_2 sigma model with zero theta angle. In the application of the Higgs branch SCFTs to the DLCQ description of "little string theories" (LSTs), the "throat" continuum is identified with the continuum of "throat" states in the holographic description of the LSTs. We also match the descriptions of the string interactions (in the "throat" region) in the DLCQ and holographic descriptions of the N=(2,0) LSTs.

IR dynamics of d = 2, = (4,4) gauge theories and DLCQ of "little string theories"

Abstract: We analyze the superconformal theories (SCFTs) which arise in the low-energy limit of = (4,4) supersymmetric gauge theories in two dimensions, primarily the Higgs branch SCFT. By a direct field theory analysis we find a continuum of ``throat''-like states localized near the singularities of the Higgs branch. The ``throat'' is similar to the ``throat'' found in the Coulomb branch of the same theories, but the full superconformal field theories of the two branches are different. A particular example is the SCFT of the 4/2 sigma model with zero theta angle. In the application of the Higgs branch SCFTs to the DLCQ description of ``little string theories'' (LSTs), the ``throat'' continuum is identified with the continuum of ``throat'' states in the holographic description of the LSTs. We also match the descriptions of the string interactions (in the ``throat'' region) in the DLCQ and holographic descriptions of the = (2,0) LSTs.

Non-supersymmetric stable vacua of M-theory

Abstract: We discuss the stability of non-supersymmetric compactifications of M-theory and string theory of the form AdS × X, and their dual non-supersymmetric interacting conformal field theories. We argue that some of the difficulties in controlling 1/N-corrections disappear in the cases that the large-N dual conformal field theory has no invariant marginal operators (and in some cases with no exactly marginal operators only). We provide several examples of such compactifications of M-theory down to AdS4.

New IR dualities in supersymmetric gauge theory in three dimensions

Abstract: We present nontrivial examples of d = 3 gauge theories with sixteen and eight supercharges which are infrared dual at special points in the moduli space. This duality is distinct from mirror symmetry. To demonstrate duality we construct the gauge theories of interest using D2-branes and orientifolds and then consider their lift to M-theory. We also discuss the strong coupling limit of orientifold two-planes and orbifolds of orientifold six-planes.

A Comment on Nonsupersymmetric Fixed Points and Duality at large N

Abstract: We review some of the problems associated with deriving field theoretic results from nonsupersymmetric AdS, focusing on how to control the behavior of the field theory along the flat directions. We discuss an example in which the origin of the moduli space remains a stable vacuum at finite N, and argue that it corresponds to an interacting CFT in three dimensions. Associated to this fixed point is a statement of nonsupersymmetric duality. Because 1/N corrections may change the global picture of the RG flow, the statement of duality is much weaker than in the supersymmetric case.

A Comment on Nonsupersymmetric Fixed Points and Duality at large N

Abstract: We review some of the problems associated with deriving field theoretic results from nonsupersymmetric AdS, focusing on how to control the behavior of the field theory along the flat directions. We discuss an example in which the origin of the moduli space remains a stable vacuum at finite $N$, and argue that it corresponds to an interacting CFT in three dimensions. Associated to this fixed point is a statement of nonsupersymmetric duality. Because 1/N corrections may change the global picture of the RG flow, the statement of duality is much weaker than in the supersymmetric case.

From SYM Perturbation Theory to Closed Strings in Matrix Theory

Abstract: For the purpose of better understanding the AdS/CFT correspondence it is useful to have a description of the theory for all values of the 't Hooft coupling, and for all $N$. We discuss such a description in the framework of Matrix theory for SYM on D4-branes, which is given in terms of quantum mechanics on the moduli space of solutions of the Nahm equations. This description reduces to both SYM perturbation theory and to closed string perturbation theory, each in its appropriate regime of validity, suggesting a way of directly relating the variables in the two descriptions. For example, it shows explicitly how holes in the world-sheets of the 't Hooft expansion close to give closed surfaces.