TY  - JOUR
A1  - Manuel, Cristina
A1  - Tolós, Laura
T1  - Transport properties of superfluid phonons in neutron stars
T2  - Universe
N2  - We review the effective field theory associated with the superfluid phonons that we use for the study of transport properties in the core of superfluid neutrons stars in their low temperature regime. We then discuss the shear and bulk viscosities together with the thermal conductivity coming from the collisions of superfluid phonons in neutron stars. With regard to shear, bulk, and thermal transport coefficients, the phonon collisional processes are obtained in terms of the equation of state and the superfluid gap. We compare the shear coefficient due to the interaction among superfluid phonons with other dominant processes in neutron stars, such as electron collisions. We also analyze the possible consequences for the r-mode instability in neutron stars. As for the bulk viscosities, we determine that phonon collisions contribute decisively to the bulk viscosities inside neutron stars. For the thermal conductivity resulting from phonon collisions, we find that it is temperature independent well below the transition temperature. We also obtain that the thermal conductivity due to superfluid phonons dominates over the one resulting from electron-muon interactions once phonons are in the hydrodynamic regime. As the phonons couple to the Z electroweak gauge boson, we estimate the associated neutrino emissivity. We also briefly comment on how the superfluid phonon interactions are modified in the presence of a gravitational field or in a moving background.
KW  - effective theories
KW  - transport coefficients
KW  - superfluid phonons
KW  - neutrino emissivity
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62147
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-621479
SN  - 2218-1997
N1  - This research was supported by the Spanish Ministerio de Economía y Competitividad under Contract FPA2016-81114-P, Ministerio de Ciencia e Innovación under Contract PID2019-110165GB-I00, and by the EU STRONG-2020 project under the program H2020-INFRAIA-2018-1, Grant Agreement No. 824093. This work was also supported by the COST Action CA16214 PHAROS: The multimessenger physics and astrophysics of neutron stars.
VL  - 7
IS  - 3, art. 59
SP  - 1
EP  - 22
PB  - MDPI
CY  - Basel
ER  -