Results 81 to 90 of about 27,933 (207)

Nonpersistence of resonant caustics in perturbed elliptic billiards

, 2011
Caustics are curves with the property that a billiard trajectory, once tangent to it, stays tangent after every reflection at the boundary of the billiard table.
Abramowitz, Birkhoff, Poncelet, RAFAEL RAMÍREZ-ROS, Rothos, SÔNIA PINTO-DE-CARVALHO, Tabachnikov, Whittaker   +7 more
core   +1 more source

Models of G time variations in diverse dimensions

, 2009
A review of different cosmological models in diverse dimensions leading to a relatively small time variation of the effective gravitational constant G is presented. Among them: 4-dimensional general scalar-tensor model, multidimensional vacuum model with
A. G. Riess, A. J. Sanders, A. Sanders, B. Boisseau, E. V. Pitjeva, H. Dehnen, I. S. Goncharenko, J. O. Dickey, J.-M. Alimi, J.-M. Alimi, K. A. Bronnikov, K. A. Bronnikov, K. A. Bronnikov, M. A. Grebeniuk, N. A. Zaitsev, R. Hellings, S. A. Kononogov, S. A. Kononogov, S. A. Kononogov, S. A. Kononogov, S. Perlmutter, U. Bleyer, V. Baukh, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. D. Ivashchuk, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. N. Melnikov, V. R. Gavrilov, V. R. Gavrilov, V. Sabbata de, Vitaly N. Melnikov, Y. Fujii, Y.-S. Wu   +51 more
core   +1 more source

Substitutional Sulfur and Its Vibrational Fingerprints in Sb2Se3

physica status solidi (RRL) – Rapid Research Letters, Volume 20, Issue 2, February 2026.
The microscopic configurations of sulfur incorporated into the Sb2$_2$Se3$_3$ lattice are studied by combining infrared absorption spectroscopy with density functional theory. Substitutional SSe$_{\mathrm{Se}}$ defects are identified as the origin of four distinct sulfur‐related local vibrational modes at 249, 273, 283, and 312 cm−1$^{-1}$.
Frank Herklotz, Eduard V. Lavrov, Vladlen V. Melnikov, Andreas Herklotz, Thomas P. Shalvey, Jon D. Major, Ken Durose   +6 more
wiley   +1 more source

Chaos in a Generalized Perturbed Lotka–Volterra Model

Mathematics
In this paper we investigate the chaos of a generalized perturbed Lotka–Volterra model based on considerations by other studies used in the literature. The model, containing N number of free parameters, could be of interest to specialists working in the ...
Nikolay Kyurkchiev, Tsvetelin Zaevski, Anton Iliev, Vesselin Kyurkchiev, Angel Golev, Asen Rahnev   +5 more
doaj   +1 more source

Top-Quark Decay at Next-to-Next-to-Leading Order in QCD

, 2013
We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and $W$ boson width effects.
Gao, Jun, Li, Chong Sheng, Zhu, Hua Xing
core   +1 more source

Long‐Term Increases in Ca2+, Mg2+, and SO42− Concentrations in the Kolyma River (1980–2022) Due To Yedoma Degradation

Global Biogeochemical Cycles, Volume 40, Issue 2, February 2026.
Abstract Permafrost degradation under a warming climate has altered hydrological and biogeochemical processes across the Arctic. Although increasing fluxes of weathering‐derived ions (e.g., Ca2+, Mg2+, and SO42−) have been reported in Arctic rivers, the underlying mechanisms and hotspots within basins remain poorly understood due to limited analysis of
Y. Tashiro, T. Hiyama, H. Kanamori, L. Lebedeva, H. Park, O. Makarieva, P. Nikitina, S. R. Fassnacht, A. Zemlianskova, O. Zhunusova, K. Suzuki   +10 more
wiley   +1 more source

Toward a standardization of cryostructure and cryogenic soil structure terminology for the field description of permafrost‐affected soils

Soil Science Society of America Journal, Volume 90, Issue 1, January/February 2026.
Abstract This paper establishes standardized terminology and field documentation protocols for cryostructures and cryogenic soil structures in permafrost‐affected soils and provides brief guidance on descriptions of ground ice morphology and ice volume estimates.
Megan L. Andersen, Mikhail Kanevskiy, Chien‐Lu Ping, M. Torre Jorgenson, Yuri Shur, Julie D. Jastrow, Roser Matamala, Erin C. Rooney, Nicolas A. Jelinski   +8 more
wiley   +1 more source

Method for Noise‐Induced Regularization in Quantum Neural Networks

Advanced Quantum Technologies, Volume 8, Issue 12, December 2025.
Controllable decoherence is proposed to be used as a regulariser for quantum neural networks. Tuning amplitude, phase, and depolarising noise strengths as hyperparameters can result in minimizing validation error during training. Hardware‐realistic noisy simulation of IBM's Kingston processor shows that inserting controllable idle intervals can achieve
Viacheslav Kuzmin, Wilfrid Somogyi, Ekaterina Pankovets, Alexey Melnikov   +3 more
wiley   +1 more source

Chaos in Periodically Perturbed Monopole + Quadrupole Like Potentials

, 1997
The motion of a particle that suffers the influence of simple inner (outer) periodic perturbations when it evolves around a center of attraction modeled by an inverse square law plus a quadrupole-like term is studied.
Letelier, P. S., Vieira, W. M.
core   +1 more source

Nomenclature and typification of sectional names in Carex (Cyperaceae)

TAXON, Volume 74, Issue 6, Page 1543-1568, December 2025.
Abstract This paper presents an updated survey of all the published names at the section rank in Carex and its formerly accepted satellite genera. We included related names at other ranks when relevant. We address validity, legitimacy, priority, typification, and – if relevant – synonymy.
Pedro Jiménez‐Mejías, James L. Reveal, Santiago Martín‐Bravo, Juan Carlos Zamora, Isabel Larridon, Anton A. Reznicek, Robert F.C. Naczi   +6 more
wiley   +1 more source