Records |
Author |
Mangano, G.; Miele, G.; Pastor, S.; Pisanti, O.; Sarikas, S. |
Title |
Updated BBN bounds on the cosmological lepton asymmetry for non-zero theta(13) |
Type |
Journal Article |
Year |
2012 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume ![sorted by Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
708 |
Issue |
1-2 |
Pages |
1-5 |
Keywords |
Neutrinos; Physics of the early Universe; Primordial asymmetries |
Abstract |
We discuss the bounds on the cosmological lepton number from Big Bang Nucleosynthesis (BBN), in light of recent evidences for a large value of the neutrino mixing angle theta(13), sin(2) theta(13) greater than or similar to 0.01 at 2 sigma. The largest asymmetries for electron and mu, tau neutrinos compatible with He-4 and H-2 primordial yields are computed versus the neutrino mass hierarchy and mixing angles. The flavour oscillation dynamics is traced till the beginning of BBN and neutrino distributions after decoupling are numerically computed. The latter contains in general, non-thermal distortion due to the onset of flavour oscillations driven by solar squared mass difference in the temperature range where neutrino scatterings become inefficient to enforce thermodynamical equilibrium. Depending on the value of theta(13), this translates into a larger value for the effective number of neutrinos, N-eff. Upper bounds on this parameter are discussed for both neutrino mass hierarchies. Values for N-eff which are large enough to be detectable by the Planck experiment are found only for the (presently disfavoured) range sin(2) theta(13) <= 0.01. |
Address |
[Pastor, Sergio] Univ Valencia, CSIC, Inst Fis Corpuscular, Ed Inst Invest, E-46071 Valencia, Spain, Email: pastor@ific.uv.es |
Corporate Author |
|
Thesis |
|
Publisher |
Elsevier Science Bv |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-2693 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000301310000001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
967 |
Permanent link to this record |
|
|
|
Author |
Beltran Jimenez, J.; Heisenberg, L.; Olmo, G.J.; Rubiera-Garcia, D. |
Title |
Born-Infeld inspired modifications of gravity |
Type |
Journal Article |
Year |
2018 |
Publication |
Physics Reports |
Abbreviated Journal |
Phys. Rep. |
Volume ![sorted by Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
727 |
Issue |
|
Pages |
1-129 |
Keywords |
Born-Infeld gravity; Astrophysics; Black holes; Cosmology; Early universe; Compact objects; Singularities |
Abstract |
General Relativity has shown an outstanding observational success in the scales where it has been directly tested. However, modifications have been intensively explored in the regimes where it seems either incomplete or signals its own limit of validity. In particular, the breakdown of unitarity near the Planck scale strongly suggests that General Relativity needs to be modified at high energies and quantum gravity effects are expected to be important. This is related to the existence of spacetime singularities when the solutions of General Relativity are extrapolated to regimes where curvatures are large. In this sense, Born-Infeld inspired modifications of gravity have shown an extraordinary ability to regularise the gravitational dynamics, leading to non-singular cosmologies and regular black hole spacetimes in a very robust manner and without resorting to quantum gravity effects. This has boosted the interest in these theories in applications to stellar structure, compact objects, inflationary scenarios, cosmological singularities, and black hole and wormhole physics, among others. We review the motivations, various formulations, and main results achieved within these theories, including their observational viability, and provide an overview of current open problems and future research opportunities. |
Address |
[Beltran Jimenez, Jose] Univ Autonoma Madrid, CSIC, Inst Fis Teor, E-28049 Madrid, Spain, Email: jose.beltran@uam.es; |
Corporate Author |
|
Thesis |
|
Publisher |
Elsevier Science Bv |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1573 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000425482900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3497 |
Permanent link to this record |
|
|
|
Author |
Reichardt, C.L.; de Putter, R.; Zahn, O.; Hou, Z. |
Title |
New limits on early dark energy from the South Pole telescope |
Type |
Journal Article |
Year |
2012 |
Publication |
Astrophysical Journal Letters |
Abbreviated Journal |
Astrophys. J. Lett. |
Volume ![sorted by Volume (numeric) field, ascending order (up)](img/sort_asc.gif) |
749 |
Issue |
1 |
Pages |
L9 - 5pp |
Keywords |
cosmic background radiation; dark energy; early universe |
Abstract |
We present new limits on early dark energy (EDE) from the cosmic microwave background (CMB) using data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite on large angular scales and South Pole Telescope on small angular scales. We find a strong upper limit on the EDE density of Omega(e) < 0.018 at 95% confidence, a factor of three improvement over WMAP data alone. We show that adding lower-redshift probes of the expansion rate to the CMB data improves constraints on the dark energy equation of state, but not the EDE density. We also explain how small-scale CMB temperature anisotropy constrains EDE. |
Address |
[Reichardt, C. L.; Zahn, O.] Univ Calif Berkeley, Dept Phys, Berkeley Ctr Cosmol Phys, Berkeley, CA 94720 USA, Email: cr@bolo.berkeley.edu |
Corporate Author |
|
Thesis |
|
Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-8205 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000302143100009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
962 |
Permanent link to this record |