arXiv subjects

Madoka Nishimura

Publications and source records attributed to Madoka Nishimura.

5 recordsLinked to original sources

arXiv2008

Chiral Symmetry Breaking in Brane Models

We discuss the chiral symmetry breaking in general intersecting Dq/Dp brane models consisting of N_c Dq-branes and a single Dp-brane with an s-dimensional intersection. There exists a QCD-like theory localized at the intersection and the Dq/Dp model gives a holographic description of it. The rotational symmetry of directions transverse to both of the Dq and Dp-branes can be identified with a chiral symmetry, which is non-Abelian for certain cases. The asymptotic distance between the Dq-branes and the Dp-brane corresponds to a quark mass. By studying the probe Dp-brane dynamics in a Dq-brane background in the near horizon and large N_c limit we find that the chiral symmetry is spontaneously broken and there appear (pseudo-)Nambu-Goldstone bosons. We also discuss the models at finite temperature.

hep-th↗

arXiv2004

Comments on Higher Derivative Terms for the Tachyon Action

We consider the open string tachyon action in a world-sheet sigma model approach. We present explicit calculations up to order 8 in derivatives for the bosonic string, and mimic these to order 6 for the superstring, including terms with multiple derivatives acting on the tachyon field. We reproduce lower derivative terms obtained elsewhere, and speculate on the role of the world-sheet contact terms regularizing the action for the superstring tachyon.

hep-th↗

arXiv2003

A Note on Supersymmetry in Noncommutative Field Theories

We show that a solution of the type IIB supergravity representing D3-branes in the presence of a 2-form background has 16 supersymmetries by explicitly constructing the transformation parameter of unbroken supersymmetry. This solution is dual to a noncommutative Yang-Mills theory in a certain limit.

hep-th↗

arXiv2001

The String Dual of an ${\cal N}=(4,0)$ Two-Dimensional Gauge Theory

We find solutions of the six-dimensional maximal supergravity by adding a perturbation of vector fields to the solution AdS${}_3$ $\times$ S${}^3$. For certain perturbations the solution represents a dual description of an ${\cal N}=(4,0)$ field theory in two dimensions by the AdS/CFT correspondence.

hep-th↗

arXiv2000

Conformal Supergravity from the AdS/CFT Correspondence

Construction of a five dimensional conformal supergravity (D=5 CSG) is attempted by applying the AdS/CFT correspondence to the F(4) AdS supergravity in six dimensions. As a first step, local transformation laws of D=5 CSG have been established, from which the Weyl weights of the various fields in D=5 can be predicted.

hep-th↗