Results 81 to 90 of about 21,366 (192)

Astrophysical constraints on superlight gravitinos [PDF]

, 1998
I review the constraints on the mass of gravitinos that follow from considerations on energy loss in stars and from Big Bang Nucleosynthesis arguments.Comment: Invited talk at the 5th Workshop on High Energy Physics Phenomenology(WHEPP-5), Pune, India,
A Mendez, F Ferrer, G Dvali, J A Grifols, J A Grifols, J A Grifols, J A Grifols, J Ellis, J. A. Grifols, K Hirata, M Dine, M Dine, M Nowakowski, M S Turner, P Binetruy, R Bionta, R N Mohapatra, T Bhattacharya   +17 more
core   +2 more sources

Absence of a Lower Limit on Omega_b in Inhomogeneous Primordial Nucleosynthesis

, 1994
We show that a class of inhomogeneous big bang nucleosynthesis models exist which yield light-element abundances in agreement with observational constraints for baryon-to-photon ratios significantly smaller than those inferred from standard homogeneous ...
Fuller, G. M., Jedamzik, K., Mathews, G. J.   +2 more
core   +1 more source

Big Bang Nucleosynthesis constraints on space-time noncommutativity

European Physical Journal C: Particles and Fields
We consider the implications of modified dispersion relations, due to the noncommutativity of spacetime, for a photon gas filling the early Universe in the framework of the Big Bang nucleosynthesis (BBN) processes, during the period of light element ...
Teodora M. Matei, Cristian A. Croitoru, Tiberiu Harko   +2 more
doaj   +1 more source

3He(α,γ)7Be cross section measured using complementary techniques

EPJ Web of Conferences, 2014
The astrophysical S-factor for the 3He(α,γ)7Be reaction plays an important role in the Solar Standard Model and in the Big Bang Nucleosynthesis scenario. The advances from two recent experiments performed using complementary techniques at center of mass (
Carmona-Gallardo M., Rojas A., Borge M.J.G., Davids B., Fulton B.R., Hass M., Nara Singh B.S., Ruiz C., Tengblad O.   +8 more
doaj   +1 more source

Spacetime deformation effect on the early universe and the PTOLEMY experiment

Physics Letters B, 2017
Using a fully-fledged formulation of gauge field theory deformed by the spacetime noncommutativity, we study its impact on relic neutrino direct detection, as proposed recently by the PTOLEMY experiment.
Raul Horvat, Josip Trampetic, Jiangyang You   +2 more
doaj   +1 more source

Big bang nucleosynthesis with a varying fine structure constant and non-standard expansion rate

, 2004
We calculate primordial abundances of light elements produced during big bang nucleosynthesis when the fine structure constant and/or the cosmic expansion rate take non-standard values.
A. Coc, B.D. Fields, C. Angulo, C.J.A. Martins, D. Kirkman, D.N. Spergel, J. Gasser, J.P. Uzan, K. Ichikawa, K.M. Nollett, Kazuhide Ichikawa, L. Bergstrom, M. Dine, M. Kawasaki, M. Kawasaki, Masahiro Kawasaki, P. Bonifacio, R.H. Cyburt, R.H. Cyburt, S. Mukohyama, S.G. Ryan, T. Shiromizu, V. Barger, V. Barger, V.F. Dmitriev, W. Hu, Y.I. Izotov   +26 more
core   +1 more source

Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy

, 2006
The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations.
A. Formicola, A. Guglielmetti, A. Lemut, B. Limata, C. Broggini, C. Gustavino, C. Rolfs, C. Rolfs, C. Rossi Alvarez, D. Bemmerer, E. Somorjai, F. Confortola, F. Strieder, F. Terrasi, G. Gervino, G. Imbriani, Gy. Gyürky, H. Costantini, H. P. Trautvetter, M. Junker, M. Laubenstein, M. Marta, O. Straniero, P. Bonifacio, P. Corvisiero, P. Prati, R. Bonetti, R. Menegazzo, V. Lozza, V. Roca, Z. Elekes, Zs. Fülöp   +31 more
core   +1 more source

Revisiting big-bang nucleosynthesis constraints on dark-matter annihilation

Physics Letters B, 2015
We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of anti-nucleons ...
Masahiro Kawasaki, Kazunori Kohri, Takeo Moroi, Yoshitaro Takaesu   +3 more
doaj   +1 more source

On the Galactic Evolution of $D$ and $^3He$

, 1993
The determined abundances of primordial $^4He$ and $^7Li$ provide a basis with which to test the standard model of big bang nucleosynthesis in conjunction with the other two light element isotopes $D$ and $^3He$, also produced in the big bang.
Olive, Keith A., Prantzos, Nikos, Vangioni-Flam, Elisabeth   +2 more
core   +2 more sources

The Spectrum of Gravitational Waves, Their Overproduction in Quintessential Inflation and Its Influence in the Reheating Temperature

Universe, 2020
One of the most important issues in an inflationary theory as standard or quintessential inflation is the mechanism to reheat the universe after the end of the inflationary period in order to match with the Hot Big Bang universe.
Jaume Haro Cases, Llibert Aresté Saló
doaj   +1 more source