There is a misconception, widely shared among physicists, that the equilibrium free energy of a one-dimensional classical model with strictly finite-ranged interactions, and at nonzero temperatures, cannot show any singularities as a function of the coupling constants. In this Letter, we discuss an instructive counterexample. We consider thin rigid linear rods of equal length 2ℓ whose centers lie on a one-dimensional lattice, of lattice spacing a. The interaction between rods is a soft-core interaction, having a finite energy U per overlap of rods. We show that the equilibrium free energy per rod F[(ℓ/a),β], at inverse temperature β, has an infinite number of singularities, as a function of ℓ/a.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.121.240601 | DOI Listing |
Phys Rev Lett
December 2024
Sandia National Laboratories, PO Box 5800, Albuquerque, New Mexico 87185, USA.
Magnetic insulation of electrons prevents losses and can be applied to generating radiation or electron sources for high current and high power applications. Ion emission from the anode may degrade magnetic insulation. We develop equilibrium theory, self-consistently coupling magnetically insulated electron flow with free-flowing injected ions.
View Article and Find Full Text PDFSci Rep
January 2025
Faculty of Informatics and Computing, Universiti Sultan Zainal Abidin, Campus Besut, 22200, Terengganu, Malaysia.
The farming of animals is one of the largest industries, with animal food products, milk, and dairy being crucial components of the global economy. However, zoonotic bacterial diseases, including brucellosis, pose significant risks to human health. The goal of this research is to develop a mathematical model to understand the spread of brucellosis in cattle populations, utilizing the Caputo-Fabrizio operator to control the disease's incidence rate.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Out of Equilibrium Group, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India.
In biological systems such as cells, the macromolecules, which are anisotropic particles, diffuse in a crowded medium. In the present work, we have studied the diffusion of spheroidal particles diffusing between cylindrical obstacles by varying the density of the obstacles as well as the spheroidal particles. Analytical calculation of the free energy showed that the orientational vector of a single oblate particle will be aligned perpendicular, and a prolate particle will be aligned parallel to the symmetry axis of the cylindrical obstacles in equilibrium.
View Article and Find Full Text PDFPLoS One
December 2024
Tandy School of Computer Science, The University of Tulsa, Tulsa, OK, United States of America.
In this manuscript, we present a novel mathematical model for understanding the dynamics of HIV/AIDS and analyzing optimal control strategies. To capture the disease dynamics, we propose a new Caputo-Fabrizio fractional-order mathematical model denoted as SEIEUPIATR, where the exposed class is subdivided into two categories: exposed-identified EI and exposed-unidentified EU individuals. Exposed-identified individuals become aware of the disease within three days, while exposed-unidentified individuals remain unaware for more than three days.
View Article and Find Full Text PDFBull Math Biol
December 2024
Centre for Data Science, Queensland University of Technology, Brisbane, 4000, Australia.
Quantitative population modelling is an invaluable tool for identifying the cascading effects of conservation on an ecosystem. When population data from monitoring programs is not available, deterministic ecosystem models have often been calibrated using the theoretical assumption that ecosystems have a stable, coexisting equilibrium. However, a growing body of literature suggests these theoretical assumptions are inappropriate for conservation contexts.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!