Superfluidity and Superconductivity in Neutron Stars

Dear Colleagues,

Formed in the aftermath of gravitational core-collapse supernova explosions, neutron stars contain matter crushed at densities exceeding that found inside the heaviest atomic nuclei and are, therefore, unique laboratories for exploring novel phases of matter under conditions so extreme that they cannot be reproduced on Earth. In particular, neutron stars are the only celestial bodies that are expected to be superfluids and superconducting. Although quantum condensates have been extensively studied in the laboratory, the properties of their stellar counterpart remain largely unknown. This stems from the tremendous gravitational pressure that matter is subjected to in a neutron star. According to theoretical calculations, various kinds of superfluid and superconducting phases may exist in different regions of the star. One of the difficulties in modeling the global dynamics of a neutron star lies in the widely different scales involved: a neutron star (whose radius is about 10 kilometers) is thought to be threaded by quantized vortices with tiny cores of about 10–100 fermis. To add to the challenge, a neutron star is so compact (having a mass between once and twice that of the Sun) that it must be ultimately described by Einstein’s theory of general relativity. On the other hand, astrophysical observations can shed light on superfluidity and superconductivity in neutron stars through remarkable phenomena, such as pulsar frequency glitches. In addition to electromagnetic observations, the advent of gravitational-wave astronomy provides another way to probe the interior of a neutron star. The main goal of this Special Issue is to review recent progress in the field, from both theoretical and observational points of view.

You can now listen to some of the author discussion from the Universe webinar “Superfluidity and Superconductivity in Neutron Stars” here: https://universe-5.sciforum.net/. This webinar provided an overview of our current understanding of superfluidity and superconductivity in neutron stars and considered what can be learned from astrophysical observations by focusing on neutron star cooling, pulsar glitches, and neutron star asteroseismology.

Prof. Dr. Nicolas Chamel
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Universe is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.