BLOG 2 — Index

Ana Caramete, PhD

List of Publications

Observational constraints on the lepton asymmetry and radiation energy density

2007

Author(s): Popa, LA (Popa, L. A.); Vasile, A (Vasile, A.)

Edited by: Trache L; Stoica S

Source: EXOTIC NUCLEI AND NUCLEAR /PARTICLE ASTROPHYSICS (II) Book Series: AIP Conference Proceedings Volume: 972 Pages: 521-525 Published Date: 2008

Abstract: By using most of the present Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) measurements we set bounds on the radiation content of the Universe and neutrino properties. We consider lepton asymmetric cosmological models parametrized by the neutrino degeneracy parameter xi(nu) and the variation of the relativistic degrees of freedom, Delta N-eff(oth), due to possible unknown physical processes during BBN.

We found 0 < xi(nu) < 0.788 (2 sigma) that implies a lepton asymmetry of the neutrino background 0.001 < L-nu < 0.661. We also found 0.079 Delta N-eff(oth) < 2.555 (2 sigma) and the contribution to the total number of relativistic degrees of freedom - 1.107 < Delta N-eff < 3.482.

These results bring an important improvement over the same parameters obtained by using the WMAP data alone, showing that the LSS measurements are useful tools in constraining the radiation content of the Universe during BBN.

Accession Number: WOS:000253372300064

Conference Title: 22nd Carpathian Summer School of Physics 2007

Conference Date: AUG 20-31, 2007

Conference Location: Sinaia, ROMANIA

Conference Sponsors: Natl Inst Phys & Nuclear Engn, Cyclotron Inst, Texas A&M Univ, Coll Stn, Romanian Natl Author Sci Res

Cosmic rays from PeV to ZeV, stellar evolution, supernova physics and gamma ray bursts

2003

Author(s): Biermann, PL (Biermann, PL); Moiseenko, S (Moiseenko, S); Ter-Antonyan, S (Ter-Antonyan, S); Vasile, A (Vasile, A)

Edited by: Sanchez NG; Parijskij YN

Source: EARLY UNIVERSE AND THE COSMIC MICROWAVE BACKGROUND: THEORY AND OBSERVATIONS Book Series: NATO Science Series II-Mathematics Physics and Chemistry Volume: 130 Pages: 489-516 Published Date: 2003

Abstract: The recent success of a proposal from some time ago to explain the spectrum of cosmic rays allows some strong conclusions to be made on the physics of supernovae: In the context of this specific proposal to explain the origin of cosmic rays, the mechanism for exploding supernovae of high mass has to be the one proposed by Bisnovatyi-Kogan more than 30 years ago, which was then based on a broader suggestion by Kardashev: A combination of the effects of rotation and magnetic fields explodes the star. Interestingly, this step then leads inevitably to some further suggestions, useful perhaps for the study of gamma ray bursts and the search of a bright standard candle in cosmology.

Accession Number: WOS:000221382600022

Conference Title: Conference of the NATO-Advanced-Study-Institute on the Early Universe and the Cosmic Microwave Background

Conference Date: SEP 07-20, 2002

Conference Location: Palermo, ITALY

Conference Sponsors: NATO Adv Study Inst