4,864 research outputs found
Relativistic Equation of state with short range correlations
Short range correlations are introduced using unitary correlation method in a
relativistic approach to the equation of state of the infinite nuclear matter
in the framework of the Hartree-Fock approximation. The effect of the
correlations in the ground state properties of the nuclear matter is studied.Comment: 4 pages, 4 figure
Evolution of the fine-structure constant in the non-linear regime
We study the evolution of the fine-structure constant, , induced by
non-linear density perturbations in the context of the simplest class of
quintessence models with a non-minimal coupling to the electromagnetic field,
in which the two available free functions (potential and gauge kinetic
function) are Taylor-expanded up to linear order. We show that the results
obtained using the spherical infall model for an infinite wavelength
inhomogeneity are inconsistent with the results of a local linearized gravity
study and we argue in favour of the second approach. We also discuss recent
claims that the value of inside virialised regions could be
significantly different from the background one on the basis of these findings.Comment: 5 pages, 3 figure
Varying Alpha Monopoles
We study static magnetic monopoles in the context of varying alpha theories
and show that there is a group of models for which the t'Hooft-Polyakov
solution is still valid. Nevertheless, in general static magnetic monopole
solutions in varying alpha theories depart from the classical t'Hooft-Polyakov
solution with the electromagnetic energy concentrated inside the core seeding
spatial variations of the fine structure constant. We show that Equivalence
Principle constraints impose tight limits on the allowed variations of alpha
induced by magnetic monopoles which confirms the difficulty to generate
significant large-scale spatial variation of the fine structure constant found
in previous works. This is true even in the most favorable case where magnetic
monopoles are the source for these variations.Comment: 8 pages, 10 figures; Version to be published in Phys. Rev.
Topological characterization of neutron star crusts
Neutron star crusts are studied using a classical molecular dynamics model
developed for heavy ion reactions. After the model is shown to produce a
plethora of the so-called "pasta" shapes, a series of techniques borrowed from
nuclear physics, condensed matter physics and topology are used to craft a
method that can be used to characterize the shape of the pasta structures in an
unequivocal way
- …