It is a pity that the real state of matter in pulsar-like stars is still not determined confidently because of the uncertainty about cold matter at supranuclear density, even 40 years after the discovery of pulsar. Nuclear matter (related to neutron stars) is one of the speculations for the inner constitution of pulsars even from the Landau’s time more than 70 years ago, but quark matter (relat...

We comment on the paper by Tanusri Ghosh and Somenath Chakrabarty, Phys. Rev. D63, 043006 (2001). In that paper it was argued that a first-order transition to quark matter in the core of a magnetar is absolutely forbidden if its magnetic field strength exceeds 1015 G. However, we show in this comment that if the quark anomalous magnetic moment and the population of higher Landau levels is taken...

Quark clustering, rather than color super-conducting, could occur in cold quark matter because of the strongly coupling between quarks at realistic baryon densities of compact stars. Although one may still not be able to calculate this conjectured matter from first principles, the inter-cluster interaction might be analogized to the interaction between inert molecules. Cold quark matter would t...

Quark clustering could occur in cold quark matter because of the strong coupling between quarks at realistic baryon densities of compact stars. Although one may still not be able to calculate this conjectured matter from first principles, the inter-cluster interaction might be analogized to the interaction between inert molecules. Cold quark matter would then crystallize in a solid state if the...

For the past 20 years it had been thought that the coexistence phase of the confined hadronic and quark matter phases, assumed to be a first order transition, was strictly excluded from neutron stars. This, however, was due to a seemingly innocuous idealization which has approximated away important physics. The reason is that neutron stars constitute multi-component bodies rather than single-co...