Universe Webinar | Superfluidity and Superconductivity in Neutron Stars
the chair
5th Universe Webinar
Superfluidity and Superconductivity in Neutron Stars
Welcome to the webinar, “Superfluidity and Superconductivity in Neutron Stars”.
Born in the aftermath of gravitational core-collapse supernova explosions, neutron stars have masses comparable to that of our Sun but with a radius of only about 12 kilometers. With densities exceeding that found inside the heaviest atomic nuclei, neutron stars are 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 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.
This webinar will provide an overview on our current understanding of superfluidity and superconductivity in neutron stars and what can be learned from astrophysical observations focusing on neutron-star cooling, pulsar glitches, and neutron-star asteroseismology.
We look forward to seeing many of you!
My best regards,
Nicolas Chamel
Date: 28 January 2022
Time: 10:00am CET | 4:00am EST | 5:00pm CST Asia
Webinar ID: 864 1105 3834
Webinar Secretariat: universe.webinar@mdpi.com
Meet Our Speakers
Prof. Dr. Nicolas Chamel
Institute of Astronomy and Astrophysics, Physics Department, Université Libre de Bruxelles, Belgium;
Prof. Nicolas Chamel earned his PhD from the University Pierre and Marie Curie in Paris, France (now Sorbonne University). He is now a senior research associate at the Institute of Astronomy and Astrophysics of Université Libre de Bruxelles in Belgium. His main research activities deal with the properties of matter under the extreme conditions prevailing in the interior of neutron stars and their role in astrophysical phenomena.
Sponsors and Partners
Organizer
The Chair of the webinar, Prof. Dr. Nicolas Chamel from the Institute of Astronomy and Astrophysics at Université Libre de Bruxelles in Belgium, gave a general introduction. After describing the basic phenomenology and the key ideas, he discussed how similar quantum phenomena were first conjectured to occur inside neutron stars.
The second presentation was focused on the theory of neutron-star cooling and was held by Dr. Peter Shternin from the Ioffe Institute in Saint Petersburg, Russia. He showed in particular how the observed thermal emission from the young neutron star lying in the Cassiopeia A supernova remnant can shed light on neutron superfluidity and proton superconductivity in the core of neutron stars.
The third speaker was Prof. Dr. Nils Andersson from the University of Southampton in the United Kingdom. He reviewed the peculiar hydrodynamics of neutron stars, and discussed in particular about the role of entrainment. He then showed how superfluidity and superconductivity impact stellar oscillations.
The last presentation was held by Dr. Brynmor Haskell from the Copernicus Astronomical Center in Warsaw, Poland and dealt with pulsar frequency glitches. These sudden increases in the rotational frequency of neutron stars are thought to be the macroscopic manifestations of the motions of individual quantized vortices.
Each presentation was followed by a Q&A and a discussion, moderated by the Chair. The webinar was offered via Zoom and required registration to attend.
Guest Editor: Prof. Dr. Nicolas Chamel
Deadline for manuscript submissions: 15 February 2022