arXiv subjects

Yuji Tachikawa

Publications and source records attributed to Yuji Tachikawa.

150 records · Page 9Linked to original sources

arXiv2005

Pouliot Type Duality via a-Maximization

We study four-dimensional N=1 Spin(10) gauge theory with a single spinor and vectors at the superconformal fixed point via the electric-magnetic duality and a-maximization. When gauge invariant chiral primary operators hit the unitarity bounds, we find that the theory with no superpotential is identical to the one with some superpotential at the infrared fixed point. The auxiliary field method in the electric theory offers a satisfying description of the infrared fixed point, which is consistent with the better picture in the magnetic theory. In particular, it gives a clear description of the emergence of new massless degrees of freedom in the electric theory.

hep-th↗

arXiv2005

Global Structure of Moduli Space for BPS Walls

We study the global structure of the moduli space of BPS walls in the Higgs branch of supersymmetric theories with eight supercharges. We examine the structure in the neighborhood of a special Lagrangian submanifold M, and find that the dimension of the moduli space can be larger than that naively suggested by the index theorem, contrary to previous examples of BPS solitons. We investigate BPS wall solutions in an explicit example of M using Abelian gauge theory. Its Higgs branch turns out to contain several special Lagrangian submanifolds including M. We show that the total moduli space of BPS walls is the union of these submanifolds. We also find interesting dynamics between BPS walls as a byproduct of the analysis. Namely, mutual repulsion and attraction between BPS walls sometimes forbid a movement of a wall and lock it in a certain position; we also find that a pair of walls can transmute to another pair of walls with different tension after they pass through.

hep-th↗

arXiv2004

Supergravity Analysis of Hybrid Inflation Model from D3--D7 System

The slow-roll inflation is a beautiful paradigm, yet the inflaton potential can hardly be sufficiently flat when unknown gravitational effects are taken into account. However, the hybrid inflation models constructed in D = 4 N = 1 supergravity can be consistent with N = 2 supersymmetry, and can be naturally embedded into string theory. This article discusses the gravitational effects carefully in the string model, using D = 4 supergravity description. We adopt the D3--D7 system of Type IIB string theory compactified on K3 x T^2/Z_2 orientifold for definiteness. It turns out that the slow-roll parameter can be sufficiently small despite the non-minimal Kahler potential of the model. The conditions for this to happen are clarified in terms of string vacua. We also find that the geometry obtained by blowing up singularity, which is necessary for the positive vacuum energy, is stabilized by introducing certain 3-form fluxes.

hep-th↗

arXiv2004

Five-dimensional Chern-Simons terms and Nekrasov's instanton counting

We extend the graviphoton-corrected prepotential of five-dimensional pure U(N) super Yang-Mills, which was originally proposed by Nekrasov, by incorporating the effect of the five-dimensional Chern-Simons term. This extension allows us to reproduce by a gauge theory calculation the partition functions of corresponding topological A-model on local toric Calabi-Yau manifolds X^m_N for all m=0,1,...,N. The original proposal corresponds to the case m=0.

hep-th↗

arXiv2002

Derivation of the linearity principle of Intriligator-Leigh-Seiberg

Utilizing the techniques recently developed for N=1 super Yang-Mills theories by Dijkgraaf, Vafa and collaborators, we derive the linearity principle of Intriligator, Leigh and Seiberg, for the confinement phase of the theories with semi-simple gauge groups and matters in a non-chiral representation which satisfies a further technical assumption.

hep-th↗

arXiv2002

Derivation of the Konishi anomaly relation from Dijkgraaf-Vafa with (Bi-)fundamental matters

We explicitly write down the Feynman rules following the work of Dijkfraaf, Vafa and collaborators for N=1 super Yang-Mills having products of SU groups as the gauge group and matter chiral superfields in adjoint, fundamental, and bi-fundamental representations without baryonic perturbations. As an application of this, we show expectation values calculated by these methods satisfy the Konishi anomaly relation.

hep-th↗