Results 61 to 70 of about 238,932 (290)

On the boundary value problems of piecewise differential equations with left-right fractional derivatives and delay

Nonlinear Analysis, 2021
In this paper, we study the multi-point boundary value problems for a new kind of piecewise differential equations with left and right fractional derivatives and delay. In this system, the state variables satisfy the different equations in different time
Yuxin Zhang, Xiping Liu, Mei Jia
doaj   +1 more source

Calculation of single-beam two-photon absorption rate of lanthanides: effective operator method and perturbative expansion

, 2004
Perturbative contributions to single-beam two-photon transition rates may be divided into two types. The first, involving low-energy intermediate states, require a high-order perturbation treatment, or an exact diagonalization.
Axe, Bloch, Brandow, Bryson, Burdick, Burdick, Ceulemans, Chang-Kui Duan, Chase, Dagenais, Denning, Downer, Downer, Downer, Duan, Duan, Duan, Gang Ruan, Gâcon, Goldstone, Hurtubise, Judd, Killingbeck, Leavitt, Lindgren, Lindgren, McCaw, Michael F. Reid, Murdoch, Reid, Schucan, Smentek, Sytsma, Thorne, Thorne, Wang   +35 more
core   +1 more source

Nash--Moser iteration and singular perturbations [PDF]

, 2011
We present a simple and easy-to-use Nash--Moser iteration theorem tailored for singular perturbation problems admitting a formal asymptotic expansion or other family of approximate solutions depending on a parameter $\eps\to 0.$ The novel feature is to ...
Texier, Benjamin, Zumbrun, Kevin
core   +2 more sources

Consensus Formation and Change are Enhanced by Neutrality

Advanced Science, EarlyView.
Neutral agents are shown to enhance both the formation and overturning of consensus in collective decision‐making. A general mathematical model and experiments with locusts and humans reveal that neutrality enables robust consensus via simple interactions and accelerates consensus change by reducing effective population size.
Andrei Sontag, Janina A. Hoffmann, Tim Rogers, Christian A. Yates   +3 more
wiley   +1 more source

An averaging theorem for a perturbed KdV equation [PDF]

Nonlinearity, 2013
25 ...
openaire   +2 more sources

Relatively bounded perturbations of J-non-negative operators

, 2022
We improve known perturbation results for self-adjoint operators in Hilbert spaces and prove spectral enclosures for diagonally dominant $J$-self-adjoint operator matrices. These are used in the proof of the central result, a perturbation theorem for $J$-
Philipp, Friedrich
core  

Linearizing and Forecasting: A Reservoir Computing Route to Digital Twins of the Brain

Advanced Science, EarlyView.
A new approach uses simple neural networks to create digital twins of brain activity, capturing how different patterns unfold over time. The method generates and recovers key dynamics even from noisy data. When applied to fMRI, it predicts brain signals and reveals distinctive activity patterns across regions and individuals, opening possibilities for ...
Gabriele Di Antonio, Tommaso Gili, Andrea Gabrielli, Maurizio Mattia   +3 more
wiley   +1 more source

Observation of nonlinear response and Onsager regression in a photon Bose-Einstein condensate

Nature Communications
The quantum regression theorem states that the correlations of a system at two different times are governed by the same equations of motion as the single-time averages. This provides a powerful framework for the investigation of the intrinsic microscopic
Alexander Sazhin, Vladimir N. Gladilin, Andris Erglis, Göran Hellmann, Frank Vewinger, Martin Weitz, Michiel Wouters, Julian Schmitt   +7 more
doaj   +1 more source

Variational perturbation approach to the Coulomb electron gas

, 2002
The efficiency of the variational perturbation theory [Phys. Rev. C {\bf 62}, 045503 (2000)] formulated recently for many-particle systems is examined by calculating the ground state correlation energy of the 3D electron gas with the Coulomb interaction.
Bachmann M, Bünemann J, Cea P, Ceperley D M, Fetter A L, Fröhlich J, Gutzwiller M C, Janis V, Krzyweck J, Lu W-F, Mahan G D, Negele J W, Noboru Fukushima, Noh H S, Okopinska A, Okopinska A, Pines D, Ruelle D, Sang Koo You, Schulman L S, Singwi K S, Stevenson P M, Talman J D, You S K, You S K   +24 more
core   +1 more source

Bioinspired Adaptive Leg‐Claw Enables Robust Perching and Grasping for UAVs

Advanced Science, EarlyView.
Inspired by owl limb morphology and bat roosting behavior, this study presents a bioinspired adaptive leg‐claw mechanism that enables UAVs to perform robust and versatile perching and grasping. The design integrates a four‐link tibial structure, tension‐driven deformable feet, and active control, enabling stable perching on various branches and ...
Tianyu Cheng, Shaokun Wang, Jiehan Zou, Guiwen Shi, Zhongxue Gan, I‐Ming Chen, Guo‐Niu Zhu   +6 more
wiley   +1 more source