Dense QCD and phenomenology of compact stars

I discuss three topics in physics of massive (two solar-mass and larger) neutron stars containing deconfined quark matter: (i) the equation of state of deconfined dense quark matter and its color superconducting phases, (ii) the thermal evolution of stars with quark cores, (iii) color-magnetic flux tubes in type-II superconducting quark matter and their dynamics driven by Aharonov-Bohm interactions with unpaired fermions.Comment: 8 pages, 3 figures. Contribution to the proceedings of "Xth Quark Confinement and the Hadron Spectrum", October 8-12, 2012, Munich, German

Exploring phases of dense QCD with compact stars

I review a number of recent developments in the physics of compact stars containing deconfined quark matter, including (a)~their cooling with possible phase transition from a fully gapped to a gapless phase of QCD at low temperatures and large isospin, (b)~the transport coefficients of the 2SC phase and the role played by the Aharonov-Bohm interactions between flux-tubes and unpaired fermions; (c)~rapidly rotating compact stars and spin-down and spin-up induced phase transition between hadronic and QCD matter as well as between different phases of QCD.Comment: 11 pages, 6 figures, Proceedings of the 5th International Conference on New Frontiers in Physics (ICNFP2016), 6-14 July 2016, Kolymbari, Crete, Greec

Rapid cooling of the compact star in Cassiopea A as a phase transition in dense QCD

We present a model of the compact star in Cassiopea A that accounts for its unusually fast cooling behavior. This feature is interpreted as an enhancement in the neutrino emission triggered by a transition from a fully gapped, two-flavor, color-superconducting phase to a crystalline phase or an alternative gapless, color-superconducting phase. By fine-tuning a single parameter -- the temperature of this transition -- a specific cooling scenario can be selected that fits the Cas A data. Such a scenario requires a massive $M\sim 2M_{\odot}$ star and is, therefore, distinctive from models invoking canonical 1.4 $M_{\odot}$ mass star with nucleonic pairing alone.Comment: 5 pages, 3 figures, v2 and v3: minor changes, matches the version publised in A & A Letter