Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Stratos Kovalkov Papadoudis

Journal of High Energy Physics 02(151) Feb 2018 [Refereed]

In recent years the complex Langevin method (CLM) has proven a powerful method in studying statistical systems which suffer from the sign problem. Here we show that it can also be applied to an important problem concerning why we live in four-dime...

Journal of High Energy Physics 09(071) Sep 2017 [Refereed]

In this paper, we study the finite-temperature matrix quantum mechanics with chemical potential term linear in the single trace of U(N) matrices, via Monte Carlo simulation. In the bosonic case, we exhibit the existence of the Gross-Witten-Wadia (...

Takehiro Azuma, Yuta Ito, Jun Nishimura, Asato Tsuchiya

Progress of Theoretical and Experimental Physics 8 Aug 2017 [Refereed]

The type IIB matrix model has been investigated as a possible nonperturbative formulation of superstring theory. In particular, it was found by Monte Carlo simulation of the Lorentzian version that the 9D rotational symmetry of the spatial matrice...

Physical Review Letters 113(091603) Mar 2014 [Refereed]

It is expected that the Gregory-Laflamme (GL) instability in the black string in gravity is related to the Rayleigh-Plateau instability in fluid mechanics. Especially, the orders of the phase transitions associated with these instabilities depend ...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Journal of High Energy Physics (11)009 Jun 2013 [Refereed]

It has long been speculated that the spontaneous symmetry breaking (SSB) of SO(D) occurs in matrix models obtained by dimensionally reducing super Yang-Mills theory in D=6,10 dimensions. In particular, the D=10 case corresponds to the IIB matrix m...

Journal of High Energy Physics (10)59 Jul 2012 [Refereed]

We study a one-dimensional large-N U(N) gauge theory on a circle as a toy model of higher dimensional Yang-Mills theories at finite temperature. To investigate the profile of the thermodynamical potential in this model, we evaluate a stochastic ti...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Journal of High Energy Physics (10)126 Aug 2011 [Refereed]

The matrix model formulation of superstring theory offers the possibility to understand the appearance of 4d space-time from 10d as a consequence of spontaneous breaking of the SO(10) symmetry. Monte Carlo studies of this issue is technically diff...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Physical Review D 83(054504) Sep 2010 [Refereed]

The sign problem is a notorious problem, which occurs in Monte Carlo simulations of a system with the partition function whose integrand is not real positive. The basic idea of the factorization method applied on such a system is to control some o...

Physics Letters B 659(3) 676-682 Oct 2007 [Refereed]

In the study of the small ten-dimensional Schwarzschild blackhole, the blackhole to string transition is an important problem. In hep-th/0605041, a possible identification is made between the Gross-Witten-Wadia (GWW) type third-order large-N phase...

Journal of High Energy Physics (03) 035 Dec 2007 [Refereed]

We discuss the classical and quantum stability of general configurations representing many fuzzy spheres in dimensionally reduced Yang-Mills-Chern-Simons models with and without supersymmetry. By performing one-loop perturbative calculations aroun...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Keiichi Nagao, Jun Nishimura

Journal of High Energy Physics (09) 046 Jun 2005 [Refereed]

We study a 4d supersymmetric matrix model with a cubic term, which incorporates fuzzy spheres as classical solutions, using Monte Carlo simulations and perturbative calculations. The fuzzy sphere in the supersymmetric model turns out to be always ...

Takehiro Azuma, Subrata Bal, Keiichi Nagao, Jun Nishimura

Journal of High Energy Physics (09) 047 Jun 2005 [Refereed]

We study a matrix model with a cubic term, which incorporates both the fuzzy S^2*S^2 and the fuzzy S^2 as classical solutions. Both of the solutions decay into the vacuum of the pure Yang-Mills model (even in the large-N limit) when the coefficien...

It has been known for some time that the dynamics of k coincident D-branes in string theory is described effectively by U(k) Yang-Mills theory at low energy. While these configurations appear as classical solutions in matrix models, it was not cle...

Journal of High Energy Physics (06) 081 Oct 2004 [Refereed]

We clarify some peculiar aspects of the perturbative expansion around a classical fuzzy-sphere solution in matrix models with a cubic term. While the effective action in the large-N limit is saturated at the one-loop level, we find that the ``one-...

Takehiro Azuma, Subrata Bal, Keiichi Nagao, Jun Nishimura

Journal of High Energy Physics (07) 066 May 2004 [Refereed]

We perform nonperturbative studies of the dimensionally reduced 5d Yang-Mills-Chern-Simons model, in which a four-dimensional fuzzy manifold, ``fuzzy S'', is known to exist as a classical solution. Although the action is unbounded from below...

Takehiro Azuma, Subrata Bal, Keiichi Nagao, Jun Nishimura

Journal of High Energy Physics (05) 061 May 2004 [Refereed]

``Fuzzy CP^2'', which is a four-dimensional fuzzy manifold extension of the well-known fuzzy analogous to the fuzzy 2-sphere (S^2), appears as a classical solution in the dimensionally reduced 8d Yang-Mills model with a cubic term involving the st...

Takehiro Azuma, Subrata Bal, Keiichi Nagao, Jun Nishimura

Journal of High Energy Physics (05) 005 Jan 2004 [Refereed]

Fuzzy spheres appear as classical solutions in a matrix model obtained via dimensional reduction of 3-dimensional Yang-Mills theory with the Chern-Simons term. Well-defined perturbative expansion around these solutions can be formulated even for f...

We investigate here a supermatrix model with a mass term and a cubic interaction. It is based on the super Lie algebra osp(1|32,R), which could play a role in the construction of the eleven-dimensional M-theory. This model contains a massive versi...

Physics Letters B 538(3/4) 393-405 Apr 2002 [Refereed]

We present a formulation of a matrix model which manifestly possesses the general coordinate invariance when we identify the large matrices with differential operators. In order to build a matrix model which has the local Lorentz invariance, w...

Takehiro Azuma, Satoshi Iso, Hikaru Kawai and Yuhi Ohwashi

Nuclear Physics B (610) 251-279 Feb 2001 [Refereed]

We investigate several matrix models based on super Lie algebras, osp(1|32,R), u(1|16,16) and gl(1|32,R). They are natural generalizations of IIB matrix model and were first proposed by Smolin. In particular, we study the supersymmetry structures ...

Progress of Theoretical Physics 106(2) 255-292 Jun 2001 [Refereed]

We analyze the operator product expansion T_{\mu \nu}(z) W[C] in N=4 4-dimensional Super-Yang-Mills (SYM) theory with U(N) gauge group, and clarify that the closed Wilson loop does not possess an anomalous dimension and that only the shape of the ...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Stratos Kovalkov Papadoudis

to be published in PoS(CORFU2018) Jun 2019

The type IIB matrix model is conjectured to be a nonperturbative definition of type IIB superstring theory. In this model, spacetime is a dynamical quantity and compactification of extra dimensions can be realized via spontaneous symmetry breaking...

In order to broaden students' horizons in science and technology, Setsunan University has established a new subject "Scientific and Technological Literacy". The Institute for Fundamental Sciences, which is in charge of teaching basic mathematics a...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Proceedings of Science LATTICE (307) Sep 2015

The IIB matrix model has been proposed as a non-perturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneously brea...

JSEE 2015 Proceedings 63 438-439 Aug 2015 [Refereed]

Mathematics is an essential prerequisite for the students of technology. Setsunan University started participating in EMaT from 2011. We report on the status quo of EMaT in Setsunan University.

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Proceedings of Science LATTICE 226 Nov 2012

The IKKT or IIB matrix model has been postulated to be a non perturbative definition of superstring theory. It has the attractive feature that spacetime is dynamically generated, which makes possible the scenario of dynamical compactification of e...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Proceedings of Science LATTICE 181 Oct 2011

The sign problem is a notorious problem, which occurs in Monte Carlo simulations of a system with a partition function whose integrand is not positive. One way to simulate such a system is to use the factorization method where one enforces samplin...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Jun Nishimura

Proceedings of Science LATTICE 167 Oct 2010

The IIB matrix model proposes a mechanism for dynamically generating four dimensional space--time in string theory by spontaneous breaking of the ten dimensional rotational symmetry . Calculations using the Gaussian expansion meth...

Bulletin of Faculty of Education, Ibaraki University (56) 91-102 2007

(English translation is submitted as arXiv:0803.3167)
Recently in the authors' country Japan, the unpopularity of natural science among children has been a serious problem. Especially, physics is unpopular because physics requires mathematics. One...

The large-N reduced models have been proposed as the nonperturbative formulation of the superstring theory. One of the most promising candidates is the IIB matrix model. While there have been a lot of interesting discoveries of the IIB matrix mode...

This paper reports the investigation of a matrix model via super Lie algebra, following the proposal of L. Smolin. We consider the osp(1|32,R) nongauged matrix model and gl(1|32,R) gauged matrix model, especially paying attention to the supersymme...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Toshiyuki Okubo, Stratos Kovalkov Papadoudis

Mandelstam Institute Seminar 30 Apr 2019 Mandelstam Institute, Wits University

The type IIB matrix model has been proposed as a non-perturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneously...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Toshiyuki Okubo, Stratos Kovalkov Papadoudis

74th annual meeting of the Physical Society of Japan 14 Mar 2019 The Physical Society of Japan

The type IIB matrix model has been proposed as a non-perturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneously...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Toshiyuki Okubo, Stratos Kovalkov Papadoudis

The 1st R-CCS International Symposium 18 Feb 2019 RIKEN Center for Computational Science (R-CCS)

The type IIB matrix model has been proposed as a non-perturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneously...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Stratos Kovalkov Papadoudis

String Theory Seminar at TIFR 21 Aug 2018 TIFR

It has been speculated that the spontaneous symmetry breakdown (SSB) of the SO(D) rotational symmetry occurs in the matrix models obtained by the dimensional reduction of the super Yang-Mills (SYM)theory in D=6,10 dimensions, with the indices cont...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Ito Yuta, Jun Nishimura, Toshiyuki Okubo, Stratos Kovalkov Papadoudis

Strings 2018 27 Jun 2018

It has been speculated that the spontaneous symmetry breakdown (SSB) of the SO(D) rotational symmetry occurs in the matrix models obtained by the dimensional reduction of the super Yang-Mills (SYM) theory in D=6,10 dimensions, with the indices con...

73rd annual meeting of the Physical Society of Japan 22 Mar 2018 The Physical Society of Japan

In this paper, we study the finite-temperature matrix quantum mechanics with chemical potential term linear in the single trace of U(N) matrices, via Monte Carlo simulation. In the bosonic case, we exhibit the existence of the Gross-Witten-Wadia (...

40th Shikoku Seminar 23 Dec 2017 Kagawa University

In this paper, we study the finite-temperature matrix quantum mechanics with chemical potential term linear in the single trace of U(N) matrices, via Monte Carlo simulation. In the bosonic case, we exhibit the existence of the Gross-Witten-Wadia (...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Stratos Kovalkov Papadoudis

ICTS-TIFR Seminar 1 Jan 2018 ICTS-TIFR, India

In recent years the complex Langevin method (CLM) has proven a powerful method in studying statistical systems which suffer from the sign problem. Here we show that it can also be applied to an important problem concerning why we live in four-dime...

Konstantinos N. Anagnostopoulos、Takehiro Azuma、Yuta Ito、Jun Nishimura、Stratos Kovalkov Papadoudis

East Asia Joint Workshop on Fields and Strings 2017, KEK Theory workshop 2017 14 Nov 2017 High-energy accelerator research orgainzation

The IIB matrix model has been proposed as a nonperturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneous breakdo...

65th JSEE annual conference 30 Aug 2017 Japanese Society for Engineering Education (JSEE)

In order to cultivate students' literacy in science, Setsunan University newly established a class "Scientific and Technological Literacy". The Institute for Fundamental Sciences, in charge of basic education of mathematics and physics, started of...

Konstantinos N. Anagnostopoulos, Takehiro Azuma, Yuta Ito, Jun Nishimura, Stratos Kovalkov Papadoudis

72nd annual meeting of the Physical Society of Japan 17 Mar 2017 The Physical Society of Japan

The IIB matrix model has been proposed as a nonperturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneous break...

TIFR String Theory Seminars 31 Dec 2015 Tata Institute of Fundamental Research

The IIB matrix model has been proposed as a nonperturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of the spontaneous bre...

63rd JSEE annual conference 4 Sep 2015 Japanese Society for Engineering Education (JSEE)

Mathematical ability is important for the students of Faculty of Engineering to study in the university. In Setsunan University, we participate in EMaT from 2011. In this talk, we report on the status quo of EMaT in Setsunan University.

JPS 70th Annual Meeting 24 Mar 2015 The Physical Society of Japan

The IIB matrix model has been proposed as a nonperturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneous break...

KEK Theory Workshop 2015 28 Jan 2015 High Energy Accelerator Research Organization

The IIB matrix model has been proposed as a nonperturbative definition of superstring theory. In this work, we study the Euclidean version of this model in which extra dimensions can be dynamically compactified if a scenario of spontaneous break...