TY - JOUR
T1 - Quantum anomalies in string-inspired running vacuum universe
T2 - Inflation and axion dark matter
AU - Basilakos, Spyros
AU - Mavromatos, Nick E.
AU - Solà Peracaula, Joan
PY - 2020/4/10
Y1 - 2020/4/10
N2 - In this letter, we elaborate further on a Cosmological “Running-Vacuum” type model for the Universe, suggested previously by the authors [1,2], within the context of a string-inspired effective theory in the presence of a Kalb-Ramond (KR) gravitational axion field which descends from the antisymmetric tensor of the massless gravitational string multiplet. In the presence of this field, which has anomalous CP violating interactions with the gravitons, primordial gravitational waves induce gravitational anomalies, which in turn are responsible for the appearance of H2 and H4 contributions to the vacuum energy density, these terms being characteristic of generic “running-vacuum-model (RVM) type”, where H is the Hubble parameter. In this work we prove in detail the appearance of the H4 terms due to gravitational-anomaly-induced condensates in the energy density of the primordial Universe, which can self-consistently induce inflation, and subsequent exit from it, according to the generic features of RVM. We also argue in favour of the robustness of our results, which were derived within an effective low-energy field theory approach, against Ultra Violet completion of the theory. During the radiation and matter-dominated eras, gravitational anomalies cancel, as required for the consistency of the quantum matter/radiation field theory. However, chiral and QCD-axion-type anomalies survive and have important consequences for both cosmic magnetogenesis and axionic dark matter in the Universe. Finally, the stringy RVM scenario presented here predicts quintessence-like dynamical dark energy for the current Universe, which is compatible with the existing fitting analyses of such model against observations.
AB - In this letter, we elaborate further on a Cosmological “Running-Vacuum” type model for the Universe, suggested previously by the authors [1,2], within the context of a string-inspired effective theory in the presence of a Kalb-Ramond (KR) gravitational axion field which descends from the antisymmetric tensor of the massless gravitational string multiplet. In the presence of this field, which has anomalous CP violating interactions with the gravitons, primordial gravitational waves induce gravitational anomalies, which in turn are responsible for the appearance of H2 and H4 contributions to the vacuum energy density, these terms being characteristic of generic “running-vacuum-model (RVM) type”, where H is the Hubble parameter. In this work we prove in detail the appearance of the H4 terms due to gravitational-anomaly-induced condensates in the energy density of the primordial Universe, which can self-consistently induce inflation, and subsequent exit from it, according to the generic features of RVM. We also argue in favour of the robustness of our results, which were derived within an effective low-energy field theory approach, against Ultra Violet completion of the theory. During the radiation and matter-dominated eras, gravitational anomalies cancel, as required for the consistency of the quantum matter/radiation field theory. However, chiral and QCD-axion-type anomalies survive and have important consequences for both cosmic magnetogenesis and axionic dark matter in the Universe. Finally, the stringy RVM scenario presented here predicts quintessence-like dynamical dark energy for the current Universe, which is compatible with the existing fitting analyses of such model against observations.
UR - http://www.scopus.com/inward/record.url?scp=85080148048&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2020.135342
DO - 10.1016/j.physletb.2020.135342
M3 - Article
AN - SCOPUS:85080148048
SN - 0370-2693
VL - 803
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
M1 - 135342
ER -