Energy density fluctuations in Early Universe

The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.Comment: 4 pages, 2 figures. Talk given at Sventh European Summer School on Experimental Nuclear Astrophysics, 15-27 September 2013, Santa Tecla (CT) - Ital

Meissner masses in the gCFL phase of QCD

We calculate the Meissner masses of gluons in neutral three-flavor color superconducting matter for finite strange quark mass. In the CFL phase the eissner masses are slowly varying function of the strange quark mass. For large strange quark mass, in the so called gCFL phase, the Meissner masses of gluons with colors $a=1,2,3$ and 8 become imaginary, indicating an instability.Comment: New Fig. 1 shows that also the masses of the gluons 3 and 8 are imaginar

Enforced neutrality and color-flavor unlocking in the three-flavor Polyakov-loop NJL model

We study how the charge neutrality affects the phase structure of three-flavor PNJL model. We point out that, within the conventional PNJL model at finite density the color neutrality is missing because the Wilson line serves as an external ``colored'' field coupled to dynamical quarks. In this paper we heuristically assume that the model may still be applicable. To get color neutrality one has then to allow non vanishing color chemical potentials. We study how the quark matter phase diagram in $(T,m_s^2/\mu)$-plane is affected by imposing neutrality and by including the Polyakov loop dynamics. Although these two effects are correlated in a nonlinear way, the impact of the Polyakov loop turns out to be significant in the $T$ direction, while imposing neutrality brings a remarkable effect in the $m_s^2/\mu$ direction. In particular, we find a novel unlocking transition, when the temperature is increased, even in the chiral SU(3) limit. We clarify how and why this is possible once the dynamics of the colored Polyakov loop is taken into account. Also we succeed in giving an analytic expression for $T_c$ for the transition from two-flavor pairing (2SC) to unpaired quark matter in the presence of the Polyakov loop.Comment: 11 pages, REVTex4, 10 eps figures; v2: added two notes, added a reference; version to appear in Phys. Rev.