The physics related to the form factors of the energy–momentum tensor spans a wide
spectrum of problems, and includes gravitational physics, hard-exclusive reactions, hadronic …

We review theoretical approaches to explore the phase diagram of nuclear and quark matter
at high baryon density. We first look over the basic properties of quantum chromodynamics …

Following previous work we further explore the possibility that the chirally broken phase of
gauge theories admits an infrared fixed point interpretation. The slope of the β function, β …

We extract the bulk viscosity of hot quark–gluon matter in the presence of light quarks from
the recent lattice data on the QCD equation of state. For that purpose we extend the sum rule …

This paper reviews various approaches used nowadays in order to understand the structure
of the ground state of the strong interaction theory, the so-called QCD vacuum. In particular …

Glueballs are particles whose valence degrees of freedom are gluons and therefore in their
description the gauge field plays a dominant role. We review recent results in the physics of …

The conception of the conformal phase transiton (CPT), which is relevant for the description
of nonperturbative dynamics in gauge theories, is introduced and elaborated. The main …

We study scalar, pseudoscalar, vector, and axial-vector mesons with nonstrange and
strange quantum numbers in the framework of a linear sigma model with global chiral U (N f) …

This review is devoted to the discussion of the parallel existing between four-dimensional
gauge theories and two-dimensional sigma models. We use sigma models as a laboratory …

Kubo's formula relates bulk viscosity to the retarded Green's function of the trace of the
energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the …