Statistical mechanics and the description of the early universe II. Principle of detailed balance and primordial 4He formation
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Statistical mechanics and the description of the early universe II. Principle of detailed balance and primordial 4He formation. / Pessah, Martin Elias; F. Torres, Diego.
In: Physica A: Statistical Mechanics and its Applications, Vol. 297, No. 1-2, 03.07.2001, p. 201-228.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Statistical mechanics and the description of the early universe II. Principle of detailed balance and primordial 4He formation
AU - Pessah, Martin Elias
AU - F. Torres, Diego
PY - 2001/7/3
Y1 - 2001/7/3
N2 - If the universe is slightly non-extensive, and the distribution functions are not exactly given by those of Boltzmann-Gibbs, the primordial production of light elements will be non-trivially modified. In particular, the principle of detailed balance (PDB), of fundamental importance in the standard analytical analysis, is no longer valid, and a non-extensive correction appears. This correction is computed and its influence is studied and compared with previous works, where, even when the universe was considered as an slightly non-extensive system, the PDB was assumed valid. We analytically track the formation of Helium and Deuterium, and study the kind of deviation one could expect from the standard regime. The correction to the capture time, the moment in which Deuterium can no longer be substantially photo-disintegrated, is also presented. This allows us to take into account the process of the free decay of neutrons, which was absent in all previous treatments of the topic. We show that even when considering a first (linear) order correction in the quantum distribution functions, the final output on the primordial nucleosynthesis yields cannot be reduced to a linear correction in the abundances. We finally obtain new bounds upon the non-extensive parameter, both comparing the range of physical viability of the theory, and using the latest observational data.
AB - If the universe is slightly non-extensive, and the distribution functions are not exactly given by those of Boltzmann-Gibbs, the primordial production of light elements will be non-trivially modified. In particular, the principle of detailed balance (PDB), of fundamental importance in the standard analytical analysis, is no longer valid, and a non-extensive correction appears. This correction is computed and its influence is studied and compared with previous works, where, even when the universe was considered as an slightly non-extensive system, the PDB was assumed valid. We analytically track the formation of Helium and Deuterium, and study the kind of deviation one could expect from the standard regime. The correction to the capture time, the moment in which Deuterium can no longer be substantially photo-disintegrated, is also presented. This allows us to take into account the process of the free decay of neutrons, which was absent in all previous treatments of the topic. We show that even when considering a first (linear) order correction in the quantum distribution functions, the final output on the primordial nucleosynthesis yields cannot be reduced to a linear correction in the abundances. We finally obtain new bounds upon the non-extensive parameter, both comparing the range of physical viability of the theory, and using the latest observational data.
KW - gr-qc
KW - astro-ph
KW - cond-mat.stat-mech
U2 - 10.1016/S0378-4371(01)00236-9
DO - 10.1016/S0378-4371(01)00236-9
M3 - Journal article
VL - 297
SP - 201
EP - 228
JO - Physica A: Statistical Mechanics and its Applications
JF - Physica A: Statistical Mechanics and its Applications
SN - 0378-4371
IS - 1-2
ER -
ID: 34383084