English
Related papers

Related papers: Imaginary-time theory for triple-alpha reaction ra…

200 papers

Context. Monte Carlo methods have enabled nuclear reaction rates from uncertain inputs to be presented in a statistically meaningful manner. However, these uncertainties are currently computed assuming no correlations between the physical…

Instrumentation and Methods for Astrophysics · Physics 2017-08-02 Richard Longland

Triple-$\alpha$ reaction rates have been determined well with the sequential process via the narrow resonances. However, the direct triple-$\alpha$ process at off-resonant energies still remains in unsolved problems. In the present report,…

Nuclear Theory · Physics 2023-03-29 M. Katsuma

This work describes the formalism for estimating thermonuclear reaction rates for astrophysical applications, emphasizing modern statistical approaches such as Monte-Carlo sampling and Bayesian models. We discuss related topics including…

Solar and Stellar Astrophysics · Physics 2026-03-11 Christian Iliadis , Richard Longland , Kiana Setoodehnia , Caleb Marshall , Peter Mohr , Athanasios Psaltis

The well-known astrophysical resonant reaction rate equations for an isolated narrow resonance have been reexamined. The validity of those `look reliable' assumptions used in deriving the analytic reaction rate equations has been checked,…

Solar and Stellar Astrophysics · Physics 2009-12-11 J. J. He

As contrast to the Maxwellian distribution, equilibrium distribution of the second kind or turbulent equilibrium is shown to exist under tertiary molecular chaos hypothesis to replace the classical binary chaos by Boltzmann. It is expressed…

Chaotic Dynamics · Physics 2007-05-23 Shunichi Tsuge

This review focuses on nuclear reactions in astrophysics and, more specifically, on reactions with light ions (nucleons and alpha particles) proceeding via the strong interaction. It is intended to present the basic definitions essential…

Nuclear Theory · Physics 2015-03-17 T. Rauscher

Confined nanoscale spaces, electric fields and tunneling currents make the molecular electronic junction an experimental device for the discovery of new, out-of-equilibrium chemical reactions. Reaction-rate theory for current-activated…

Mesoscale and Nanoscale Physics · Physics 2021-04-27 Riley J. Preston , Maxim F. Gelin , Daniel S. Kosov

The astrophysical S--factor and reaction rates for the triple--alpha process are calculated in the direct--capture model. It is shown that the stellar carbon production is extremely sensitive to small variations in the N--N interaction.

Astrophysics · Physics 2015-06-24 H. Oberhummer , H. Krauss , K. Grün , T. Rauscher , H. Abele , P. Mohr , G. Staudt

The astrophysical S--factor and reaction rates for the triple--alpha process are calculated in the direct--capture model. It is shown that the stellar carbon production is extremely sensitive to small variations in the N--N interaction.

Nuclear Theory · Physics 2009-10-22 H. Oberhummer , H. Krauss , K. Grün , T. Rauscher , H. Abele , P. Mohr , G. Staudt

The problem of calculating real-time correlation functions is formulated in terms of an imaginary-time partial differential equation. The latter is solved analytically for the perturbed harmonic oscillator and compared with the known exact…

Statistical Mechanics · Physics 2007-05-23 P. E. Kornilovitch

We investigate the triple-alpha reaction at low energies, by assuming a direct process. The Coulomb potential of three $\alpha$ particles is examined carefully. The three-body continuum wave functions are generated by calculating an…

Nuclear Theory · Physics 2013-08-20 Y. Suzuki , P. Descouvemont

Interacting-Particle Reaction Dynamics (iPRD) simulates the spatiotemporal evolution of particles that experience interaction forces and can react with one another. The combination of interaction forces and reactions enable a wide range of…

Chemical Physics · Physics 2018-07-20 Christoph Fröhner , Frank Noé

A new alternate method for evaluating linear response theory is formally developed, and results are presented. This method involves the time-evolution of the system using TDHF and is constructed directly on top of a static Hartree-Fock…

Nuclear Theory · Physics 2009-11-11 A. S. Umar , V. E. Oberacker

While seemingly straightforward in principle, the reliable estimation of rate constants is seldom easy in practice. Numerous issues, such as the complication of poor reaction coordinates, cause obvious approaches to yield unreliable…

The molecular algebraic model based on three and four alpha clusters is used to describe the inelastic scattering of alpha particles populating low-lying states in $^{12}$C and $^{16}$O. Optical potentials and inelastic formfactors are…

Nuclear Theory · Physics 2021-02-03 J. Casal , L. Fortunato , E. G. Lanza , A. Vitturi

Canonical instanton theory is a widespread approach to describe the dynamics of chemical reactions in low temperature environments when tunneling effects become dominant. It is a semiclassical theory which requires locating classical…

Chemical Physics · Physics 2020-09-15 Andreas Löhle , Johannes Kästner

Nuclear reaction rates determine the abundances of isotopes in stellar burning processes. A multitude of reactions determine the reaction flow pattern which is described in terms of reaction network simulations. The reaction rates are…

Instrumentation and Methods for Astrophysics · Physics 2010-11-03 M. Wiescher , T. Rauscher

The methodology for modeling grain-surface chemistry has been greatly improved by taking into account the grain size and fluctuation effects. However, the reaction rate coefficients currently used in all practical models of gas-grain…

Astrophysics of Galaxies · Physics 2014-11-20 Ingo Lohmar , Joachim Krug , Ofer Biham

A dilute system of reacting particles transported by fluid flows is considered. The particles react as $A + A \to \varnothing$ with a given rate when they are within a finite radius of interaction. The system is described in terms of the…

Chaotic Dynamics · Physics 2015-06-12 Giorgio Krstulovic , Massimo Cencini , Jeremie Bec

We propose an experimental study of adaptive time-stepping methods for efficient modeling of the aggregation-fragmentation kinetics. Precise modeling of this phenomena usually requires utilization of the large systems of nonlinear ordinary…

Numerical Analysis · Mathematics 2025-01-20 Sergey A. Matveev , Viktor Zhilin , Alexander P. Smirnov