English
Related papers

Related papers: A Study of the Point Spread Function in SDSS Image…

200 papers

We consider a smooth forward facing step defined by the Gauss error function of height 4-30\% and four times the width of the local boundary layer thickness $\delta_{99}$. The boundary layer flow over a smooth forward-facing stepped plate…

Fluid Dynamics · Physics 2016-03-11 Hui Xu , Jean-Eloi W. Lombard , Spencer J. Sherwin

We study the properties of energy flux in wave turbulence via the Majda-McLaughlin-Tabak (MMT) equation with a quadratic dispersion relation. One of our purposes is to resolve the inter-scale energy flux $P$ in the stationary state to…

Fluid Dynamics · Physics 2022-03-02 Alexander Hrabski , Yulin Pan

Point spread function (PSF) engineering has been pivotal in the remarkable progress made in high-resolution imaging in the last decades. However, the diversity in PSF structures attainable through existing engineering methods is limited.…

Optics · Physics 2025-06-10 Md Sadman Sakib Rahman , Aydogan Ozcan

There have been increasing reports that the diffusion coefficient of macromolecules depends on time and fluctuates randomly. Here, a novel method to elucidate the fluctuating diffusivity from trajectory data is developed. The time-averaged…

Statistical Mechanics · Physics 2017-10-25 Tomoshige Miyaguchi

The probability density function of single-point velocity fluctuations in turbulence is studied systematically using Fourier coefficients in the energy-containing range. In ideal turbulence where energy-containing motions are random and…

Fluid Dynamics · Physics 2009-11-10 H. Mouri , M. Takaoka , A. Hori , Y. Kawashima

In this paper we discuss recent applications of the Smoothed Particle Hydrodynamics (SPH) method to the simulation of supersonic turbulence in the interstellar medium, as well as giving an update on recent algorithmic developments in…

Instrumentation and Methods for Astrophysics · Physics 2010-02-26 Daniel J. Price , Christoph Federrath

We introduce a new technique, called the Sliding Two-Dimensional Fluctuation Spectrum, used for detecting and characterising the temporal changes of drifting subpulses from radio pulsars. The method was tested using simulated data as well…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. Serylak , B. W. Stappers , P. Weltevrede

We present the development of a data-driven, AI-based model of the Point Spread Function (PSF) that achieves higher accuracy than the current state-of-the-art approach, "PSF in the Full Field-of-View'' (PIFF). PIFF is widely used in leading…

Instrumentation and Methods for Astrophysics · Physics 2026-02-18 Dayana Andrea Henao Arbeláez , Pierre-François Léget , Andrés Alejandro Plazas Malagón

We report experiments on the full space and time resolved statistics of capillary wave turbulence at the air-water interface. The three-dimensional shape of the free interface is measured as a function of time by using the optical method of…

Fluid Dynamics · Physics 2013-03-18 Michael Berhanu , Eric Falcon

The power spectrum, $S$, of horizontal transects of plankton abundance are often observed to have a power-law dependence on wavenumber, $k$, with exponent close to -2: $S(k)\propto k^{-2}$ over a wide range of scales. I present power…

ao-sci · Physics 2008-02-03 Jon D. Pelletier

Turbulent dynamics generate random fluctuations in density and velocity in the Interstellar Medium (ISM) of spiral and dwarf galaxies. Observationally, H~{\sc i} 21-cm radiation provides a good probe of these stochastic processes and helps…

Astrophysics of Galaxies · Physics 2018-05-30 Meera Nandakumar

Dispersion curves characterize the frequency dependence of the phase and the group velocities of propagating elastic waves. Many analytical and numerical techniques produce dispersion curves from physics-based models. However, it is often…

Data Analysis, Statistics and Probability · Physics 2021-10-26 V. V. N. Sriram Malladi , Mohammad I. Albakri , Manu Krishnan , Serkan Gugercin , Pablo A. Tarazaga

Two-way coupled DNS simulation of particle-laden turbulent Couette-flow [1], in the volume fraction regime $\phi>10^{-4}$, showed a discontinuous decrease of turbulence intensity beyond a critical volume fraction…

Fluid Dynamics · Physics 2022-04-04 Swagnik Ghosh , Partha Sarathi Goswami

We explore the multi-faceted important features of turbulence (e.g., anisotropy, dispersion, diffusion) in the three-dimensional (3D) wavenumber domain ($k_\parallel$, $k_{\perp,1}$, $k_{\perp,2}$), by employing the k-filtering technique to…

Plasma Physics · Physics 2022-11-30 Rong Lin , Jiansen He , Xingyu Zhu , Lei Zhang , Die Duan , Fouad Sahraoui , Daniel Verscharen

Scanning Kelvin probe microscopy (SKPM) is a powerful technique for investigating the electrostatic properties of material surfaces, enabling the imaging of variations in work function, topology, surface charge density, or combinations…

Applied Physics · Physics 2024-07-26 Isaac C. D. Lenton , Felix Pertl , Lubuna Shafeek , Scott R. Waitukaitis

Recently, there has been interest in determining the viscoelastic properties of polymeric liquids and other complex fluids by means of Diffusing Wave Spectroscopy (DWS). In this technique, light-scattering spectroscopy is applied to highly…

Soft Condensed Matter · Physics 2024-08-27 George D. J. Phillies

The point-spread function (PSF) of an imaging system describes the response of the system to a point source. Accurately determining the PSF enables one to correct for the combined effects of focussing and scattering within the imaging…

Instrumentation and Methods for Astrophysics · Physics 2022-11-01 Stefan Johann Hofmeister , Michael Hahn , Daniel Wolf Savin

Turbulence models, such as the Smagorinsky model herein, are used to represent the energy lost from resolved to under-resolved scales due to the energy cascade (i.e. non-linearity). Analytic estimates of the energy dissipation rates of a…

Numerical Analysis · Mathematics 2019-04-24 Ali Pakzad

Light propagation in turbulent media is conventionally studied with the help of the spatio-temporal power spectra of the refractive index fluctuations. In particular, for natural water turbulence several models for the spatial power spectra…

Atmospheric and Oceanic Physics · Physics 2021-01-28 Jinren Yao , Hantao Wang , Huajun Zhang , Jiandong Cai , Mingyuan Ren , Yu Zhang , Olga Korotkova

We use $^{12}$CO (J=1-0) MWISP data to study turbulence in a segment of the Local Arm. Velocity slices at different kinematic distances show similar spatial power spectra (SPSs) and structure functions (SFs), demonstrating that the entire…

Astrophysics of Galaxies · Physics 2025-11-18 Yuehui Ma , Miaomiao Zhang , Hongchi Wang , Xuepeng Chen , Zhenyi Yue , Suziye He , Xiangyu Ou , Li Sun