TY  - JOUR
A1  - Vovchenko, Volodymyr
A1  - Brandt, Bastian Benjamin
A1  - Cuteri, Francesca
A1  - Endrődi, Gergely
A1  - Hajkarim, Fazlollah
A1  - Schaffner-Bielich, Jürgen
T1  - Pion condensation in the early universe at nonvanishing lepton flavor asymmetry and its gravitational wave signatures
T2  - Physical review letters
N2  - We investigate the possible formation of a Bose-Einstein condensed phase of pions in the early Universe at nonvanishing values of lepton flavor asymmetries. A hadron resonance gas model with pion interactions, based on first-principle lattice QCD simulations at nonzero isospin density, is used to evaluate cosmic trajectories at various values of electron, muon, and tau lepton asymmetries that satisfy the available constraints on the total lepton asymmetry. The cosmic trajectory can pass through the pion condensed phase if the combined electron and muon asymmetry is sufficiently large: |le+lμ|≳0.1, with little sensitivity to the difference le−lμ between the individual flavor asymmetries. Future constraints on the values of the individual lepton flavor asymmetries will thus be able to either confirm or rule out the condensation of pions during the cosmic QCD epoch. We demonstrate that the pion condensed phase leaves an imprint both on the spectrum of primordial gravitational waves and on the mass distribution of primordial black holes at the QCD scale, e.g., the black hole binary of recent LIGO event GW190521 can be formed in that phase.
KW  - Evolution of the Universe
KW  - Gravitational waves
KW  - Lattice QCD
KW  - QCD phase transitions
KW  - Quantum chromodynamics
KW  - Bose-Einstein condensates
KW  - Astronomical masses & mass distributions
KW  - Ab initio calculations
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/83785
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-837858
SN  - 1079-7114
N1  - Funded by SCOAP3.
N1  - Funding: U.S. Department of Energy, Office of Science, Office of Nuclear Physics ; DE-AC02-05CH11231231
N1  - Funding: DFG ;  CRC-TR 211 ; 315477589-TRR 211
N1  - Funding: DFG ; EN 1064/2-1
N1  - Funding: Alexander von Humboldt foundation ; Feodor Lynen program
N1  - Funding: Supporting TAlent in ReSearch@University of Padova (STARS@UNIPD) ; “New Theoretical Tools for Axion Cosmology”
VL  - 126
IS  - art. 012701
SP  - 1
EP  - 7
PB  - APS
CY  - College Park, Md.
ER  -