Witten index and phase diagram of compactified N=1 supersymmetric Yang-Mills theory on the lattice

Owing to confinement, the fundamental particles of N=1 Supersymmetric Yang-Mills (SYM) theory, gluons and gluinos, appear only in colourless bound states at zero temperature. Compactifying the Euclidean time dimension with periodic boundary conditions for fermions preserves supersymmetry, and confinement is predicted to persist independently of the length of the compactified dimension. This scenario can be tested non-perturbatively with Monte-Carlo simulations on a lattice. SUSY is, however, broken on the lattice and can be recovered only in the continuum limit. The partition function of compactified N=1 SYM theory with periodic fermion boundary conditions corresponds to the Witten index. Therefore it can be used to test whether supersymmetry is realized on the lattice. Results of our recent numerical simulations are presented, supporting the disappearance of the deconfinement transition in the supersymmetric limit and the restoration of SUSY at low energies.Comment: 7 pages, 3 figures, Proceedings of the 33rd International Symposium on Lattice Field Theory (Lattice 2015), 14-18 July 2015, Kobe International Conference Center, Kobe, Japa

Phase structure of the N=1 supersymmetric Yang-Mills theory at finite temperature

Supersymmetry (SUSY) has been proposed to be a central concept for the physics beyond the standard model and for a description of the strong interactions in the context of the AdS/CFT correspondence. A deeper understanding of these developments requires the knowledge of the properties of supersymmetric models at finite temperatures. We present a Monte Carlo investigation of the finite temperature phase diagram of the N=1 supersymmetric Yang-Mills theory (SYM) regularised on a space-time lattice. The model is in many aspects similar to QCD: quark confinement and fermion condensation occur in the low temperature regime of both theories. A comparison to QCD is therefore possible. The simulations show that for N=1 SYM the deconfinement temperature has a mild dependence on the fermion mass. The analysis of the chiral condensate susceptibility supports the possibility that chiral symmetry is restored near the deconfinement phase transition.Comment: 26 pages, 12 figure

Introduction

Species categories are not simply an invention of the human mind. Plants, animals, fungi, and viruses engage in species making by mingling and separating.1 Yet, at the same time, the boundaries that define or differentiate species are not simply natural ; they are actively made, maintained, politically charged, and fashioned to serve some needs more than others, inviting new essentialisms even as they alert us to important differences. Like other rubrics for organizing social worlds—race, ethnicity, gender, age, ability—the concept of species and the alternative classifications it invites are complicated and controversial. Whether wild or domestic, pet or pest, such categories are subject to temporally fluctuating human motives, shifting values, and cultural diversities

Introduction

Species categories are not simply an invention of the human mind. Plants, animals, fungi, and viruses engage in species making by mingling and separating.1 Yet, at the same time, the boundaries that define or differentiate species are not simply natural ; they are actively made, maintained, politically charged, and fashioned to serve some needs more than others, inviting new essentialisms even as they alert us to important differences. Like other rubrics for organizing social worlds—race, ethnicity, gender, age, ability—the concept of species and the alternative classifications it invites are complicated and controversial. Whether wild or domestic, pet or pest, such categories are subject to temporally fluctuating human motives, shifting values, and cultural diversities

Fluctuations in the presence of fields -Phenomenological Gaussian approximation and a new class of thermodynamic inequalities-

The work approaches the study of the fluctuations for the thermodynamic systems in the presence of the fields. The approach is of phenomenological nature and developed in a Gaussian approximation. The study is exemplified on the cases of a magnetizable continuum in a magnetoquasistatic field, as well as for the so called discrete systems. In the last case one finds that the fluctuations estimators depends both on the intrinsic properties of the system and on the characteristics of the environment. Following some earlier ideas of one of the authors we present a new class of thermodynamic inequalities for the systems investigated in this paper. In the case of two variables the mentioned inequalities are nothing but non-quantum analogues of the well known quantum Heisenberg (''uncertainty'') relations. Also the obtained fluctuations estimators support the idea that the Boltzmann's constant k has the signification of a generic indicator of stochasticity for thermodynamic systems. Pacs number(s): 05.20.-y, 05.40.-a, 05.70.-a, 41.20.GzComment: preprint, 24 page

Monte Carlo simulation of SU(2) Yang-Mills theory with light gluinos

In a numerical Monte Carlo simulation of SU(2) Yang-Mills theory with light dynamical gluinos the low energy features of the dynamics as confinement and bound state mass spectrum are investigated. The motivation is supersymmetry at vanishing gluino mass. The performance of the applied two-step multi-bosonic dynamical fermion algorithm is discussed.Comment: latex, 48 pages, 16 figures with epsfi

Gribov no-pole condition, Zwanziger horizon function, Kugo-Ojima confinement criterion, boundary conditions, BRST breaking and all that

We aim to offer a kind of unifying view on two popular topics in the studies of nonperturbative aspects of Yang-Mills theories in the Landau gauge: the so-called Gribov-Zwanziger approach and the Kugo-Ojima confinement criterion. Borrowing results from statistical thermodynamics, we show that imposing the Kugo-Ojima confinement criterion as a boundary condition leads to a modified yet renormalizable partition function. We verify that the resulting partition function is equivalent with the one obtained by Gribov and Zwanziger, which restricts the domain of integration in the path integral within the first Gribov horizon. The construction of an action implementing a boundary condition allows one to discuss the symmetries of the system in the presence of the boundary. In particular, the conventional BRST symmetry is softly broken.Comment: 5 pages. v2 matches version to appear in PhysRevD (RC