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Methods used to infer nuclear parameters from neutron count statistics fall into two categories depending on whether they use moments or count number probabilities. As probabilities are in general more difficult to calculate, we are…

Nuclear Theory · Physics 2024-08-12 Philippe Humbert

We propose a formulation of an absorbing boundary for a quantum particle. The formulation is based on a Feynman-type integral over trajectories that are confined by the absorbing boundary. Trajectories that reach the absorbing wall are…

Quantum Physics · Physics 2007-05-23 A. Marchewka , Z. Schuss

First order phase transitions proceed via nucleation. The rate of nucleation varies exponentially with the free-energy barrier to nucleation, and so is highly sensitive to variations in this barrier. In practice, very few systems are…

Statistical Mechanics · Physics 2009-11-10 Richard P. Sear

Fractional generalizations of the Poisson process and branching Furry process are considered. The link between characteristics of the processes, fractional differential equations and Levy stable densities are discussed and used for…

Statistical Mechanics · Physics 2010-02-15 Vladimir V. Uchaikin , Dexter O. Cahoy , Renat T. Sibatov

The electron neutron scattering process determines the electrical and thermal conductivity of neutron stars plasma. As we approach the resonance section of the growth is much higher than the growth predicted by the perturbation theory. The…

General Physics · Physics 2017-04-25 B. A. Veklenko , A. A. Vasiljeva

We develop a stochastic formulation of cosmology in the early universe, after considering the scatter in the redshift-apparent magnitude diagram in the early epochs as an observational evidence for the non-deterministic evolution of early…

Astrophysics · Physics 2015-06-24 C. Sivakumar , Moncy V. John , K. Babu Joseph

The neutron transport equation (NTE) describes the flux of neutrons across a planar cross-section in an inhomogeneous fissile medium when the process of nuclear fission is active. Classical work on the NTE emerges from the applied…

Probability · Mathematics 2020-03-18 Simon C. Harris , Emma Horton , Andreas E. Kyprianou

Although the detailed conditions for explosive nucleosynthesis are derived from astrophysical modeling, nuclear physics determines fundamental patterns in abundance yields, not only for equilibrium processes. Focussing on the nu-p- and the…

Solar and Stellar Astrophysics · Physics 2013-04-04 T. Rauscher , C. Fröhlich

The Feynman-Hellmann method, as implemented by Bouchard et al. [1612.06963], was recently employed successfully to determine the nucleon axial charge. A limitation of the method was the restriction to a single operator and a single momentum…

The differential rates and emissivities of neutrino pairs from an equilibrium plasma are calculated for the wide range of density and temperature encountered in astrophysical systems. New analytical expressions are derived for the…

Astrophysics · Physics 2009-11-07 Sasa Ratkovic , Sharada Iyer Dutta , Madappa Prakash

The issue of averaging randomness is addressed, mostly in nuclear physics, but shortly also in QCD. The Feshbach approach, so successful in dealing with the continuum spectrum of the atomic nuclei ("optical model"), is extended to encompass…

Nuclear Theory · Physics 2017-08-23 A. De Pace , A. Molinari

The paper considers the well-known Galton-Watson stochastic branching process. We are dealing with a non-critical case. In the subcritical case, when the mean of the direct descendants of one particle per generation of the time step is less…

Probability · Mathematics 2022-05-09 Azam Imomov , Misliddin Murtazaev

We revisit the work of Mitter and Newton on an information-theoretic interpretation of Bayes' formula through the Gibbs variational principle. This formulation allowed them to pose nonlinear estimation for diffusion processes as a problem…

Optimization and Control · Mathematics 2024-05-02 Maxim Raginsky

Results on the behaviour of the rightmost particle in the $n$th generation in the branching random walk are reviewed and the phenomenon of anomalous spreading speeds, noticed recently in related deterministic models, is considered. The…

Probability · Mathematics 2010-03-25 J. D. Biggins

In this paper, a pricing formula for volatility swaps is delivered when the underlying asset follows the stochastic volatility model with jumps and stochastic intensity. By using Feynman-Kac theorem, a partial integral differential equation…

Pricing of Securities · Quantitative Finance 2018-05-21 Ben-zhang Yang , Jia Yue , Ming-hui Wang , Nan-jing Huang

In a recent paper we demonstrated how the simplest model for varying alpha may be interpreted as the effect of a dielectric material, generalized to be consistent with Lorentz invariance. Unlike normal dielectrics, such a medium cannot…

General Relativity and Quantum Cosmology · Physics 2015-09-03 John D. Barrow , Joao Magueijo

We investigate, by numerical simulation, the path probability of non dissipative mechanical systems undergoing stochastic motion. The aim is to search for the relationship between this probability and the usual mechanical action. The model…

Statistical Mechanics · Physics 2015-06-17 T. L. Lin , R. Wang , W. P. Bi , A. El Kaabouchi , C. Pujos , F. Calvayrac , Q. A. Wang

We present a perturbation theory by extending a prescription due to Feynman for computing the probability density function for the random flight motion. The method can be applied to a wide variety of otherwise difficult circumstances. The…

Classical Physics · Physics 2007-05-23 S. Tim Hatamian

By formulating the axioms of quantum mechanics, von Neumann also laid the foundations of a "quantum probability theory". As such, it is regarded a generalization of the "classical probability theory" due to Kolmogorov. Outside of quantum…

Quantum Physics · Physics 2025-11-17 Maik Reddiger

A stochastic representation for the solutions of the Poisson-Vlasov equation is obtained. The representation involves both an exponential and a branching process. The stochastic representation, besides providing an alternative existence…

Plasma Physics · Physics 2007-09-27 R. Vilela Mendes , Fernanda Cipriano