arXiv subjects

Fukuichiro Kubo

Publications and source records attributed to Fukuichiro Kubo.

3 recordsLinked to original sources

arXiv2007

Phase structure of the large-N reduced gauge theory and generalized Weingarten model

We study a generalization of Weingarten model reduced to a point, which becomes the large-N reduced U(N) gauge theory in a special limit. We find that the U(1)^d symmetry is broken one by one, and restored simultaneously as U(1)^d -> U(1)^{d-1} -> ... -> U(1) -> 1 -> U(1)^d as we change the coupling constants. In this model we can develop an efficient algorithm and we can see the phase structure of large-N reduced model clearly, and therefore this model would be useful for the study of the unitary model.

hep-th↗

arXiv2007

String tension and string susceptibility in two-dimensional generalized Weingarten model

We study the two-dimensional generalized Weingarten model reduced to a point, which interpolates reduced Weingarten model and the large-N gauge theory. We calculate the expectation value of the Wilson loop using Monte-Carlo method and determine the string tension and string susceptibility. The numerical result suggests that the string susceptibility approaches to -2 in a certain parametric region, which implies that the branched-polymer configurations are suppressed.

hep-th↗

arXiv2004

Fuzzy Torus in Matrix Model

We have calculated the free energy up to two loop to compare T^2 with T^4 in IIB matrix model. It turns out that T^2 has smaller free energy than T^4. We have also discussed the generation of the gauge group by considering k-coincident fuzzy tori and found that in this case U(1) gauge group is favored. This means that if the true vacuum is four-dimensional, it is not a simple fuzzy space considered here.

hep-th↗