scholarly journals Analysis of the multicomponent relativistic Boltzmann equation for electron scattering in big bang nucleosynthesis

2020 ◽  
Vol 101 (12) ◽  
Author(s):  
Nishanth Sasankan ◽  
Atul Kedia ◽  
Motohiko Kusakabe ◽  
Grant J. Mathews
Keyword(s):  
Boltzmann Equation ◽  
Electron Scattering ◽  
Big Bang ◽  
Big Bang Nucleosynthesis ◽  
Relativistic Boltzmann Equation

scholarly journals On the Determinant Problem for the Relativistic Boltzmann Equation

2021 ◽  
Author(s):  
James Chapman ◽  
Jin Woo Jang ◽  
Robert M. Strain
Keyword(s):  
Boltzmann Equation ◽  
Upper Bound ◽  
Numerical Study ◽  
Jacobian Determinant ◽  
Large Role ◽  
Relativistic Boltzmann Equation ◽  
Relativistic Analog ◽  
Relativistic Collision ◽  
Pointwise Limit ◽  
Open Question

AbstractThis article considers a long-outstanding open question regarding the Jacobian determinant for the relativistic Boltzmann equation in the center-of-momentum coordinates. For the Newtonian Boltzmann equation, the center-of-momentum coordinates have played a large role in the study of the Newtonian non-cutoff Boltzmann equation, in particular we mention the widely used cancellation lemma [1]. In this article we calculate specifically the very complicated Jacobian determinant, in ten variables, for the relativistic collision map from the momentum p to the post collisional momentum $$p'$$ p ′ ; specifically we calculate the determinant for $$p\mapsto u = \theta p'+\left( 1-\theta \right) p$$ p ↦ u = θ p ′ + 1 - θ p for $$\theta \in [0,1]$$ θ ∈ [ 0 , 1 ] . Afterwards we give an upper-bound for this determinant that has no singularity in both p and q variables. Next we give an example where we prove that the Jacobian goes to zero in a specific pointwise limit. We further explain the results of our numerical study which shows that the Jacobian determinant has a very large number of distinct points at which it is machine zero. This generalizes the work of Glassey-Strauss (1991) [8] and Guo-Strain (2012) [12]. These conclusions make it difficult to envision a direct relativistic analog of the Newtonian cancellation lemma in the center-of-momentum coordinates.

Refined big bang nucleosynthesis constraints onΩBandNν

1994 ◽  
Vol 72 (21) ◽  
pp. 3309-3312 ◽  
Author(s):  
Peter J. Kernan ◽  
Lawrence M. Krauss
Keyword(s):  
Big Bang ◽  
Big Bang Nucleosynthesis

scholarly journals A construction of the general relativistic Boltzmann equation

1984 ◽  
Vol 7 (3) ◽  
pp. 591-597 ◽  
Author(s):  
P. Dolan ◽  
A. C. Zenios
Keyword(s):  
Distribution Function ◽  
Boltzmann Equation ◽  
Kinetic Equation ◽  
Simple Model ◽  
State Space ◽  
Differential Forms ◽  
Relativistic Boltzmann Equation ◽  
Dimensional State Space ◽  
General Relativistic ◽  
Invariant Differential

Our work depends essentially on the notion of a one-particle seven-dimensional state-space. In constructing a general relativistic theory we assume that all measurable quantities arise from invariant differential forms. In this paper, we study only the case when instantaneous, binary, elastic collisions occur between the particles of the gas. With a simple model for colliding particles and their collisions, we derive the kinetic equation, which gives the change of the distribution function along flows in state-space.

scholarly journals Searching for space-time variation of the fine structure constant using QSO spectra: overview and future prospects

2009 ◽  
Vol 5 (H15) ◽  
pp. 304-304
Author(s):  
J. C. Berengut ◽  
V. A. Dzuba ◽  
V. V. Flambaum ◽  
J. A. King ◽  
M. G. Kozlov ◽  
...  
Keyword(s):  
Nuclear Reactor ◽  
Structure Constant ◽  
Big Bang ◽  
The Other ◽  
Fine Structure Constant ◽  
Spatial And Temporal Variation ◽  
Fundamental Constants ◽  
Future Prospects ◽  
Big Bang Nucleosynthesis ◽  
The Universe

Current theories that seek to unify gravity with the other fundamental interactions suggest that spatial and temporal variation of fundamental constants is a possibility, or even a necessity, in an expanding Universe. Several studies have tried to probe the values of constants at earlier stages in the evolution of the Universe, using tools such as big-bang nucleosynthesis, the Oklo natural nuclear reactor, quasar absorption spectra, and atomic clocks (see, e.g. Flambaum & Berengut (2009)).

Big Bang nucleosynthesis as a probe of varying fundamental “constants”

2007 ◽  
Author(s):  
Thomas Dent ◽  
Steffen Stern ◽  
Christof Wetterich ◽  
Arttu Rajantie ◽  
Carlo Contaldi ◽  
...  
Keyword(s):  
Big Bang ◽  
Fundamental Constants ◽  
Big Bang Nucleosynthesis

scholarly journals Big-bang nucleosynthesis in a Brans-Dicke cosmology with a varying $\mathsf{\Lambda}$ term related to WMAP

2006 ◽  
Vol 448 (1) ◽  
pp. 23-27 ◽  
Author(s):  
R. Nakamura ◽  
M. Hashimoto ◽  
S. Gamow ◽  
K. Arai
Keyword(s):  
Big Bang ◽  
Big Bang Nucleosynthesis
Sign in / Sign up

Export Citation Format

Share Document