The standard picture of the loop expansion associates a factor of variant Planck's over 2pi with each loop, suggesting that the tree diagrams are to be associated with classical physics, while loop effects are quantum mechanical in nature. We discuss counterexamples wherein classical effects arise from loop diagrams and display the relationship between the classical terms and the long range effects of massless particles.
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http://dx.doi.org/10.1103/PhysRevLett.93.201602 | DOI Listing |
Math Med Biol
December 2024
Escuela de Ingeniería Civil Informática, Universidad de Valparaíso, General Cruz 222, Valparaíso, Chile.
The linear functional analysis, historically founded by Fourier and Legendre (Fourier's supervisor), has provided an original vision of the mathematical transformations between functional vector spaces. Fourier, and later Laplace and Wavelet transforms, respectively defined using the simple and damped pendulum, have been successfully applied in numerous applications in Physics and engineering problems. However the classical pendulum basis may not be the most appropriate in several problems, such as biological ones, where the modelling approach is not linked to the pendulum.
View Article and Find Full Text PDFPLoS One
December 2024
Department of Mathematics & Statistics, Jordan University of Science and Technology, Irbid, Jordan.
This study presents a novel approach to metric spaces through the lens of geometric calculus, redefining traditional structures with new operations and properties derived from non-Newtonian measures. Specifically, we develop and prove geometric versions of the Hölder and Minkowski inequalities, which provide foundational support for applying these spaces in analysis. Additionally, we establish key relationships between geometric and classical metric spaces, examining concepts such as openness, closedness, and separability within this geometric framework.
View Article and Find Full Text PDFChaos
December 2024
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
In the classical control of network systems, the control actions on a node are determined as a function of the states of all nodes in the network. Motivated by applications where the global state cannot be reconstructed in real time due to limitations in the collection, communication, and processing of data, here we introduce a control approach in which the control actions can be computed as a function of the states of the nodes within a limited state information neighborhood. The trade-off between the control performance and the size of this neighborhood is primarily determined by the condition number of the controllability Gramian.
View Article and Find Full Text PDFJ Chem Theory Comput
December 2024
Max Planck Institute for the Structure and Dynamics of Matter, Luruper Ch 149, Hamburg 22761, Germany.
High-harmonic generation (HHG) is a nonlinear process in which a material sample is irradiated by intense laser pulses, causing the emission of high harmonics of incident light. HHG has historically been explained by theories employing a classical electromagnetic field, successfully capturing its spectral and temporal characteristics. However, recent research indicates that quantum-optical effects naturally exist or can be artificially induced in HHG, such as entanglement between emitted harmonics.
View Article and Find Full Text PDFBiomed Khim
December 2024
Chemistry Department, Lomonosov Moscow State University, Moscow, Russia; Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Moscow, Russia.
The phosphorylation reaction, catalyzed by the enzyme protein kinase A (PKA), plays one of the key roles in the work of the glutamatergic system, primarily involved in memory functioning. The analysis of the dynamic behavior of the enzyme-substrate complex allows one to learn the mechanism of the enzymatic reaction. According to the results of classical molecular dynamics calculations followed by hierarchical clustering, the most preferred proton acceptor during the phosphorylation reaction catalyzed by PKA is the carboxyl group of the amino acid residue Asp166; however, the γ-phosphate group of ATP can also act as an acceptor.
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