On unification of gravitation and electromagnetism in the framework of a general-relativistic approach

We consider the unification problem for the gravitational and electromagnetic interactions and its possible solution on the basis of the existence of an effective Riemannian space in nonlinear electrodynamicsComment: 3 pages, Talk given at the International Conference RUSGRAV-13, June 23-28, 2008, PFUR, Mosco

A local gauge invariant infrared regularization of the Yang-Mills theory

A local gauge invariant infrared regularization for the Yang-Mills theory is constructed on the basis of a higher derivative formulation of the model.Comment: 7 page

Multiphonon anharmonic decay of a quantum mode

A nonperturbative theory of multiphonon anharmonic transitions between energy levels of a local mode is presented. It is shown that the rate of transitions rearranges near the critical level number $n_{cr}$: at smaller $n$ the process slows down, while at larger $n$ it accelerates in time, causing a jump-like loss of energy followed by the generation of phonon bursts. Depending on parameters, phonons are emitted in pairs, triplets etc.Comment: submitted to Europhys.Let

Influence of high magnetic fields on superconducting transition of one-dimensional Nb and MoGe nanowires

The effects of strong magnetic field on superconducting Nb and MoGe nanowires with diameter $\sim10$ nm have been studied. We have found that the Langer-Ambegaokar-McCumber-Halperin (LAMH) theory of thermally activated phase slips is applicable in a wide range of magnetic fields and describes well the temperature dependence of the wire resistance, over eleven orders of magnitude. The field dependence of the critical temperature, $T_{c}$, extracted from the LAMH fits is in good quantitative agreement with the theory of pair-breaking perturbations that takes into account both spin and orbital contributions. The extracted spin-orbit scattering time agrees with an estimate $\tau_{so}\simeq \tau(\hbar c/ Ze^{2})^{4}$, where $\tau$ is the elastic scattering time and $Z$ is the atomic number.Comment: accepted for publication in Physical Review Letter