arXiv subjects

Tomoki Nosaka

Publications and source records attributed to Tomoki Nosaka.

41 records · Page 3Linked to original sources

arXiv2015

Exact Instanton Expansion of Superconformal Chern-Simons Theories from Topological Strings

It was known that the ABJM matrix model is dual to the topological string theory on a Calabi-Yau manifold. Using this relation it was possible to write down the exact instanton expansion of the partition function of the ABJM matrix model. The expression consists of a universal function constructed from the free energy of the refined topological string theory with an overall topological invariant characterizing the Calabi-Yau manifold. In this paper we explore two other superconformal Chern-Simons theories of the circular quiver type. We find that the partition function of one theory enjoys the same expression from the refined topological string theory as the ABJM matrix model with different topological invariants while that of the other is more general. We also observe an unexpected relation between these two theories.

hep-th↗

arXiv2015

ABJM Membrane Instanton from Pole Cancellation Mechanism

The coefficients of the membrane instantons in the ABJM theory are known to be quadratic polynomials of the chemical potential. We show that, after deforming the ABJM theory into more general superconformal Chern-Simons theories labelled by (q,p) where the original ABJM theory corresponds to (q,p)=(1,1), we can decompose the membrane instanton into three types of non-perturbative effects with constant coefficients independent of the chemical potential. We find that, although these constants contain poles at certain values of q and p including the ABJM case, all of the poles cancel among themselves and the finite quadratic polynomial coefficients are reproduced at these values. This is similar to what happens between the membrane instantons and the worldsheet instantons in the ABJM theory.

hep-th↗

arXiv2014

Partition Functions of Superconformal Chern-Simons Theories from Fermi Gas Approach

We study the partition function of three-dimensional ${\mathcal N}=4$ superconformal Chern-Simons theories of the circular quiver type, which are natural generalizations of the ABJM theory, the worldvolume theory of M2-branes. In the ABJM case, it was known that the perturbative part of the partition function sums up to the Airy function as $Z(N)=e^{A}C^{-1/3}\mathrm{Ai}[C^{-1/3}(N-B)]$ with coefficients $C$, $B$ and $A$ and that for the non-perturbative part the divergences coming from the coefficients of worldsheet instantons and membrane instantons cancel among themselves. We find that many of the interesting properties in the ABJM theory are extended to the general superconformal Chern-Simons theories. Especially, we find an explicit expression of $B$ for general ${\mathcal N}=4$ theories, a conjectural form of $A$ for a special class of theories, and cancellation in the non-perturbative coefficients for the simplest theory next to the ABJM theory.

hep-th↗

arXiv2013

Supersymmetric Gauge Theories on a Squashed Four-Sphere

We define a squashed four-sphere by a dimensional reduction of a twisted S^4 x S^1, and construct explicitly a supersymmetric Yang-Mills action on it. The action includes a non-trivial dilaton factor and a theta term with a non-constant theta. The partition function of this theory is calculated using the localization technique. The resulting partition function can be written in the form consistent with the AGT relation due to the non-constant theta term. The parameter b which characterizes the partition function in this form is not restricted to be real for the squashed four-sphere.

hep-th↗

arXiv2012

M5-branes in ABJM theory and Nahm equation

We construct BPS solutions representing M2-M5 bound state in the ABJM action explicitly. They include the funnel type solutions and 't Hooft Polyakov monopole solutions. Furthermore, we give a one to one correspondence between the solutions of the BPS equation and the ones of an extended Nahm equation which includes the Nahm equation. This enables us to construct infinitely many conserved quantities from the Lax form of the Nahm equation.

hep-th↗