Instanton-dyon ensembles reproduce deconfinement and chiral restoration phase transitions

Paradigm shift in gauge topology at finite temperatures, from the instantons to their constituents -- instanton-dyons -- has recently lead to studies of their ensembles and very significant advances. Like instantons, they have fermionic zero modes, and their collectivization at sufficiently high density explains the {\em chiral symmetry breaking transition}. Unlike instantons, these objects have electric and magnetic charges. Simulations of the instanton-dyon ensembles have demonstrated that their back reaction on the Polyakov line modifies its potential and generates the {\em deconfinement phase transition}. For the $N_c=2$ gauge theory the transition is second order, for QCD-like theory with $N_c=2$ and two light quark flavors $N_f=2$ both transitions are weak crossovers at happening at about the same condition. Introduction of quark-flavor-dependent periodicity phases (imaginary chemical potentials) leads to drastic changes in both transitions. In particulaly, in the so called $Z(N_c)-QCD$ model the deconfinement transforms to strong first order transition, while the chiral condensate does not disappear at all. The talk will also cover more detailed studies of correlations between the dyons, effective eta' mass and other screening masses.Comment: this is a short version of a talk at Lattice 2017, written for proceedings. arXiv admin note: text overlap with arXiv:1610.0878

The sounds of the Little and Big Bangs

Studies of heavy ion collisions have discovered that tiny fireballs of new phase of matter -- quark gluon plasma (QGP) -- undergoes explosion, called the Little Bang. In spite of its small size, it is not only well described by hydrodynamics, but even small perturbations on top of the explosion turned to be well described by hydrodynamical sound modes. The cosmological Big Bang also went through phase transitions, the QCD and electroweak ones, which are expected to produce sounds as well. We discuss their subsequent evolution and hypothetical inverse acoustic cascade, amplifying the amplitude. Ultimately, collision of two sound waves leads to formation of gravity waves, with the smallest wavelength. We briefly discuss how those can be detected.Comment: This paper is a short semi-popular review describing some recent developments in two very different fields, united by some common physics. It was written for the Universe journa

The Instanton Density at Finite Temperatures

For {\it low} T new strict results for the instanton density n(T) are reported. Using the PCAC methods, we express n(T) in terms of {\it vacuum} average values of certain operators, times their {\it calculated} T-dependence. At high T, we discuss the {\it applicability} limits of the perturbative results. We further speculate about possible behaviour of n(T) at $T\sim T_c$

Finite Temperature Phase Diagrams of Gauge Theories

We discuss finite temperature phase diagrams of SU(N) gauge theory with massless fermions as a function of the number of fermion flavors. Inside the conformal window we find a phase boundary separating two different conformal phases. Below the conformal window we find different phase structures depending on if the beta function of the theory has a first or higher order zero at the lower boundary of the conformal window. We also outline how the associated behaviors will help in distinguishing different types of theories using lattice simulations.Comment: 5 pages, 5 figure