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We improve the test of the gravitational inverse-square law at the submillimeter range by suppressing the vibration of the electrostatic shielding membrane to reduce the disturbance coupled from the residual surface potential. The result shows that, at a 95% confidence level, the gravitational inverse-square law holds (|α|≤1) down to a length scale λ=48 μm. This work establishes the strongest bound on the magnitude α of the Yukawa violation in the range of 40-350 μm, and improves the previous bounds by up to a factor of 3 at the length scale λ≈70 μm. Furthermore, the constraints on the power-law potentials are improved by about a factor of 2 for k=4 and 5.
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http://dx.doi.org/10.1103/PhysRevLett.124.051301 | DOI Listing |
J Chem Phys
August 2025
DNRF Centre "Glass and Time," Department of Science and Environment, Roskilde University, P.O. Box 260, DK-4000 Roskilde, Denmark.
In simulations of galaxies and structures in the universe, the particle-particle-particle-mesh "PPPM" (P3M) or "TreePM" approximations are used. The forces from objects at large distances are replaced by forces localized at meshes, and solving the Poisson equation determines their effect on an object. The particle-mesh approximation (PM) breaks the symmetry of pair interactions between objects and destroys the exact conservation of momentum and angular momentum.
View Article and Find Full Text PDFRev Sci Instrum
November 2023
INFN - Sezione di Roma Tor Vergata, Roma, Italy.
We describe a proof-of-principle experiment aiming to investigate the inverse-square law of gravitation at the centimeter scale. The sensor is a two-stage torsion pendulum, while actuation is accomplished by a variable liquid mass. The time-varying gravitational force is related to the level of the circulating fluid in one or two containers at a short distance from the test mass, with all moving mechanical parts positioned at a large distance.
View Article and Find Full Text PDFPhys Rev Lett
September 2022
MOE Key Laboratory of Fundamental Physical Quantities Measurement and Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
The center-of-mass motion of optically trapped dielectric nanoparticles in a vacuum is extremely well decoupled from its environment, making a powerful tool for measurements of feeble subattonewton forces. We demonstrate a method to trap and maneuver nanoparticles in an optical standing wave potential formed by retroreflecting a laser beam from a metallic mirror surface. We can reliably position a ∼170 diameter silica nanoparticle at distances of a few hundred nanometers to tens of micrometers from the surface of a gold-coated silicon mirror by transferring it from a single-beam tweezer trap into the standing wave potential.
View Article and Find Full Text PDFPLoS One
January 2022
Windsong Associates, Richland Center, WI, United States of America.
The model is based on a vector representation of each agent. The components of the vector are the key continuous "attributes" that determine the social behavior of the agent. A simple mathematical force vector model is used to predict the effect of each agent on all other agents.
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