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Semiconductor lasers with time-delayed optical feedback display a wide range of dynamical regimes, which have found various practical applications. They also provide excellent testbeds for data analysis tools for characterizing complex…

We examine characteristic properties of deterministic and stochastic diffusion in low-dimensional chaotic dynamical systems. As an example, we consider a periodic array of scatterers defined by a simple chaotic map on the line. Adding…

Chaotic Dynamics · Physics 2009-11-07 R. Klages

In this article, we consider elliptic diffusion problems with an anisotropic random diffusion coefficient. We model the notable direction in terms of a random vector field and derive regularity results for the solution's dependence on the…

Numerical Analysis · Mathematics 2016-07-20 Helmut Harbrecht , Michael Peters , Marc Schmidlin

Airy beams are known for displaying shape invariance and self-acceleration along the transverse direction while they propagate forwards. Although these properties could be associated with the beam coherence, it has been revealed that they…

Quantum Physics · Physics 2022-11-17 R. Martínez-Herrero , A. S. Sanz

We study transient patterns appearing in a class of SPDE using the framework of quasi-stationary and quasi-ergodic measures. In particular, we prove the existence and uniqueness of quasi-stationary and quasi-ergodic measures for a class of…

Probability · Mathematics 2024-06-19 Zachary P. Adams

We present a computationally efficient model that describes the interaction of intense, ultrashort infrared laser pulses with transparent materials in the strong ionization regime. The model is augmented with a detailed self-consistent…

Plasma Physics · Physics 2026-03-20 Julia Apportin , Christian Peltz , Pavel Polynkin , Misha Ivanov , Thomas Fennel , Anton Husakou

We study in detail a one-dimensional lattice model of a continuum, conserved field (mass) that is transferred deterministically between neighbouring random sites. The model falls in a wider class of lattice models capturing the joint effect…

Statistical Mechanics · Physics 2023-11-01 Stefano Lepri , Paolo Politi , Arkady Pikovsky

Score-based diffusion models learn to reverse a stochastic differential equation that maps data to noise. However, for complex tasks, numerical error can compound and result in highly unnatural samples. Previous work mitigates this drift…

Machine Learning · Statistics 2023-06-12 Aaron Lou , Stefano Ermon

The reaction-diffusion master equation (RDME) is commonly used to model processes where both the spatial and stochastic nature of chemical reactions need to be considered. We show that the RDME in many cases is inconsistent with a…

Quantitative Methods · Quantitative Biology 2009-05-29 Paul Sjoberg , Otto G Berg , Johan Elf

Quantum and collisional effects on the unstable spectrum of a relativistic electron beam-plasma system are investigated through a two-fluids model. Application is made to the near target center interaction of the relativistic electron beam…

Plasma Physics · Physics 2015-05-13 A. Bret , F. J. Marín Fernández , J. M. Anfray

We derive a model for a single mode laser that includes all two particle quantum correlations between photons and electrons. In contrast to the predictions of semi-classical models, we find that lasing takes place in the presence of quantum…

Coherent Diffractive Imaging is a lensless technique that allows imaging of matter at a spatial resolution not limited by lens aberrations. This technique exploits the measured diffraction pattern of a coherent beam scattered by periodic…

Computational Physics · Physics 2025-08-27 Alessandro Colombo , Davide Emilio Galli , Liberato De Caro , Francesco Scattarella , Elvio Carlino

A theory for multiple scattering of elastic waves is presented in a random medium bounded by two ideal free surfaces, whose horizontal size is infinite and whose transverse size is smaller than the mean free path of the waves. This geometry…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Nicolas P. Tregoures , Bart A. van Tiggelen

A numerical study is presented of one-dimensional and two-dimensional random lasers as a function of the pumping rate above the threshold for lasing. Depending on the leakiness of the cavity modes, we observe that the stationary lasing…

Optics · Physics 2011-08-17 Jonathan Andreasen , Patrick Sebbah , Christian Vanneste

We measure the coherent scattering of light by a cloud of laser-cooled atoms with a size comparable to the wavelength of light. By interfering a laser beam tuned near an atomic resonance with the field scattered by the atoms we observe a…

The crossover among two or more types of diffusive processes represents a vibrant theme in nonequilibrium statistical physics. In this work we propose two models to generate crossovers among different L\'evy processes: in the first model we…

Statistical Mechanics · Physics 2020-09-15 Maike A. F. dos Santos , Fernando D. Nobre , Evaldo M. F. Curado

We study experimentally and theoretically the polarization alternation during the switch-on transient of a quasi-isotropic CO$_2$ laser emitting on the fundamental mode. The observed transient dynamics is well reproduced by means of a model…

Optics · Physics 2009-11-07 I. Leyva , E. Allaria , R. Meucci

The dynamics and radiation of ultrarelativistic electrons in strong counterpropagating laser beams are investigated. Assuming that the particle energy is the dominant scale in the problem, an approximate solution of classical equations of…

Plasma Physics · Physics 2021-06-21 Q. Z. Lv , E. Raicher , C. H. Keitel , K. Z. Hatsagortsyan

With the help of a simple rate equation model, we analyze the intrinsic dynamics of threshold crossing for Class B lasers. A thorough discussion of the characteristics and the limitations of this very commonly employed model, which provides…

Optics · Physics 2016-01-11 G. P. Puccioni , T. Wang , G. L. Lippi

Deep learning (DL) has successfully automated dose distribution prediction in radiotherapy planning, enhancing both efficiency and quality. However, existing methods suffer from the over-smoothing problem for their commonly used L1 or L2…

Computer Vision and Pattern Recognition · Computer Science 2024-07-10 Zhenghao Feng , Lu Wen , Jianghong Xiao , Yuanyuan Xu , Xi Wu , Jiliu Zhou , Xingchen Peng , Yan Wang
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