arXiv subjects

S. I. Tzenov

Publications and source records attributed to S. I. Tzenov.

4 recordsLinked to original sources

arXiv2005

Hydrodynamic covariant symplectic structure from bilinear Hamiltonian functions

Starting from generic bilinear Hamiltonians, constructed by covariant vector, bivector or tensor fields, it is possible to derive a general symplectic structure which leads to holonomic and anholonomic formulations of Hamilton equations of motion directly related to a hydrodynamic picture. This feature is gauge free and it seems a deep link common to all interactions, electromagnetism and gravity included. This scheme could lead toward a full canonical quantization.

gr-qc↗

arXiv2004

Kinetic Derivation of the Hydrodynamic Equations for Capillary Fluids

Based on the generalized kinetic equation for the one-particle distribution function with a small source, the transition from the kinetic to the hydrodynamic description of many-particle systems is performed. The basic feature of this new technique to obtain the hydrodynamic limit is that the latter has been partially incorporated into the kinetic equation itself. The hydrodynamic equations for capillary fluids are derived from the characteristic function for the local moments of the distribution function. The Fick's law appears as a consequence of the transformation law for the hydrodynamic quantities under time inversion.

physics.flu-dyn↗

arXiv1998

Coherent Nonlinear Phenomena in High Energy Synchrotrons: Observations and Theoretical Models

Nonlinear waves have been observed in synchrotrons for years but have received little attention in the literature. While pathological, these phenomena are worth studying on at least two accounts. First, the formation of solitary waves may lead to droplet formation that causes significant beam halo to develop. Secondly, a variety of nonlinear processes are likely involved in the normal saturation of unstable oscillations, leading to the possibility that low-level, but potentially broadband fluctuation spectra may develop. Both features carry indirectly the signature of the machine impedance. In this work we review a number of observations of nonlinear longitudinal waves made in Fermilab accelerators, and make a first attempt to develop appropriate theoretical models to explain these observations.

physics.acc-ph↗

arXiv1998

Solitary Waves on a Coasting High-Energy Stored Beam

In this work we derive evolution equations for the nonlinear behavior of a coasting beam under the influence of a resonator impedance. Using a renormalization group approach we find a set of coupled nonlinear equations for the beam density and the resonator voltage. Under certain conditions, these may be analytically solved yielding solitary wave behavior, even in the presence of significant dissipation in the resonator. We find long-lived perturbations, i.e. droplets, which separate from the beam and decelerate towards a quasi-equilibrium state, in good agreement with simulation results.

physics.acc-ph↗