The Basset-Boussinesq-Oseen (BBO) equation correctly describes the nonuniform motion of a spherical particle at a low Reynolds number. It contains an integral term with a singular kernel which accounts for the diffusion of vorticity around the particle throughout its entire history. However, if there are any departures in either rigidity or shape from a solid sphere, besides the integral force with a singular kernel, the Basset history force, we should add a second history force with a non-singular kernel, related to the shape or composition of the particle. In this work, we introduce a fractional generalized Basset-Boussinesq-Oseen equation which includes both history terms as fractional derivatives. Using the Laplace transform, an integral representation of the solution is obtained. For a driven single particle, the solution shows that memory effects persist indefinitely under rather general driving conditions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1140/epje/s10189-021-00151-5 | DOI Listing |
In order to address the issue of low effective bandwidth ratio in off-axis digital holography, which is caused by the impact of zeroth- and first-order terms on the first-order term, an improved digital holographic reconstruction algorithm by zeroth-order term elimination based on the Riesz transform is proposed in this paper. First, an off-axis hologram is convolved with the Riesz kernels. Then, in the spectrum, the zeroth-order term is effectively eliminated by a singularity at the origin of the Riesz kernels, which can improve the effective bandwidth ratio and make the best use of the bandwidth.
View Article and Find Full Text PDFMath Ann
June 2024
Department of Mathematics, ETH Zürich, Rämistrasse 101, 8092 Zürich, Switzerland.
This article studies the canonical Hilbert energy on a Riemannian manifold for , with particular focus on the case of closed manifolds. Several equivalent definitions for this energy and the fractional Laplacian on a manifold are given, and they are shown to be identical up to explicit multiplicative constants. Moreover, the precise behavior of the kernel associated with the singular integral definition of the fractional Laplacian is obtained through an in-depth study of the heat kernel on a Riemannian manifold.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
Instituto de Física Corpuscular, Universitat de València-Consejo Superior de Investigaciones Científicas, Parc Científic, E-46980 Paterna, Valencia, Spain.
We propose multiloop vacuum amplitudes in the loop-tree duality (LTD) as the optimal building blocks for efficiently assembling theoretical predictions at high-energy colliders. This hypothesis is strongly supported by the manifestly causal properties of the LTD representation of a vacuum amplitude. The vacuum amplitude in LTD, acting as a kernel, encodes all the final states contributing to a given scattering or decay process through residues in the on-shell energies of the internal propagators.
View Article and Find Full Text PDFNAR Genom Bioinform
September 2024
Department of Applied Mathematics and Statistics, The State University of New York, Korea, Incheon 21985, South Korea.
The effect of a treatment on a health or disease response can be modified by genetic or microbial variants. It is the matter of interaction effects between genetic or microbial variants and a treatment. To powerfully discover genetic or microbial biomarkers, it is crucial to incorporate such interaction effects in addition to the main effects.
View Article and Find Full Text PDFSci Rep
September 2024
Hebei Key Laboratory of Immune Mechanism of Major Infectious Diseases and New Technology of Diagnosis and Treatment, The Fifth Hospital of Shijiazhuang, Shijiazhuang, China.
The escalating frequency of environmental pollution incidents has raised significant concerns regarding the potential health impacts of pollutant fluctuations. Consequently, a comprehensive study on the role of pollutants in the prevalence of viral hepatitis is indispensable for the advancement of innovative prevention strategies. Monthly incidence rates of viral hepatitis from 2005 to 2020 were sourced from the Chinese Center for Disease Control and Prevention Infectious Disease Surveillance Information System.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!