相关论文: Shear viscosity due to phonons in superfluid neutr…
The phonon contribution to the shear viscosity $\eta$ in superfluid neutron stars is calculated by assuming neutron pairing in a $^1S_0$ channel. The shear viscosity is obtained by means of variational methods for the solution of the…
We analyze how recent computations of the shear viscosity $\eta$ in the core of superfluid neutron stars affect the r-mode instability window. We first analyze the contribution of superfluid phonons to the viscosity, both in their…
We study the shear and bulk viscosity coefficients as well as the thermal conductivity as arising from the collisions among phonons in superfluid neutron stars. We use effective field theory techniques to extract the allowed phonon…
We present a detailed analysis of the contribution of small-angle Nambu-Goldstone boson (phonon) collisions to the shear viscosity, $\eta$, in a superfluid atomic Fermi gas close to the unitarity limit. We show that the experimental values…
We calculate the shear viscosity $\eta = \eta_{e\mu}+\eta_{n}$ in a neutron star core composed of nucleons, electrons and muons ($\eta_{e\mu}$ being the electron-muon viscosity, mediated by collisions of electrons and muons with charged…
We review the effective field theory associated with the superfluid phonons that we use for the study of transport properties in the core of superfluid neutrons stars in their low temperature regime. We then discuss the shear and bulk…
We calculate the three bulk viscosity coefficients as arising from the collisions among phonons in superfluid neutron stars. We use effective field theory techniques to extract the allowed phonon collisional processes, written as a function…
We compute the contribution of phonons to the thermal conductivity in the core of superfluid neutron stars. We use effective field theory techniques to extract the phonon scattering rates, written as a function of the equation of state of…
We discuss the effects of superfluidity on the shear viscosity in a neutron star core. Our study combines existing theoretical results for the viscosity coefficients with data for the various superfluid energy gaps into a consistent…
We analyze the effect of restricted geometries on the contribution of Nambu-Goldstone bosons (phonons) to the shear viscosity, $\eta$, of a superfluid. For illustrative purpose we examine a simplified system consisting of a circular…
Shear viscosity $\eta$ is calculated for the nuclear matter described as a system of interacting nucleons with the van der Waals (VDW) equation of state. The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of the…
The rich phenomena of the shear viscosity (eta) to entropy density (s) ratio, eta/s, in weakly coupled N-component scalar field theories are studied. eta/s can have a "double dip" behavior due to resonances and the phase transition. If an…
We study viscosity of the neutron star matter and $r$-mode instability in rotating neutron stars. Contributions to the shear and bulk viscosities from various processes are calculated with account of in-medium modifications of the…
The determination of the shear viscosity is a central topic in various areas of modern physics. In particular, it is often necessary to evaluate the shear viscosity $\eta$ of fluids made up of more than one species, all interacting with…
Viscosity plays a critical role in determining the stability of rotating neutron stars. We report the results of a calculation of the shear viscosity of $\beta$~-~stable matter, carried out using an effective interaction based on a…
The shear viscosity tensor of the A_1-phase of superfluid 3He is calculated at low temperatures and melting pressure, by using Boltzmann equation approach. The two normal and superfluid components take part in elements of the shear…
The shear viscosity of the crust might have a damping effect on the amplitude of r-modes of rotating neutron stars. This damping has implications for the emission of gravitational waves. We calculate the contribution to the shear viscosity…
Nuclear multifragmentation in intermediate energy heavy ion collisions has long been associated with liquid-gas phase transition. We calculate the shear viscosity to entropy density ratio eta/s for an equilibrated system of nucleons and…
The ratio of shear viscosity ($\eta$) to entropy density ($s$) for an equilibrated system is investigated in intermediate energy heavy ion collisions below 100$A$ MeV within the framework of the Boltzmann-Uehling-Uhlenbeck (BUU) model .…
We calculate the shear viscosity $\eta$ and thermal conductivity $\kappa$ of a nuclear pasta phase in neutron star crusts. This involves complex non-spherical shapes. We use semiclassical molecular dynamics simulations involving 40,000 to…