Renormalization group analysis of stochastic and turbulent systems

In our works we apply quantum field methods developed initially to describe interactions between elementary particles to the problems of statistical physics, namely to the fully developed hydrodynamic turbulence. The general feature of such models of statistical physics like critical behaviour and turbulence is presence of strong fluctuations, and, therefore, the presence of divergences in perturbation theory and absence of small perturbation parameter. In this…

AG Draconis, a mystery older than the Republic

Interacting variable stars, to which symbiotic binary stars belong, are  among the most exciting objects that a variety of variable stars offer. Physical mechanisms related to transfer and accretion of matter cause observable activity by manifesting increases of brightness (about 2 – 5 mag) and significant changes in the spectra of these objects. The brightenings of symbiotic systems have been recorded since the early 20th…

Deformable spin-1/2 antiferromagnetic XXZ Heisenberg chain in a magnetic field

We consider a deformable spin-1/2 antiferromagnetic XXZ Heisenberg chain and examine the spin-chain lattice compressibility as well as the sound velocity as a function of an external magnetic field applied either along the z axis or along the x axis. For strong fields, we observe a noticeable increase (with jump and hysteresis) of the lattice compressibility. Our findings are obtained by several complimentary approaches (Jordan-Wigner…