November 18th, 2021


Гравитационно-волновая гастрономия

Из серии "искусство заголовка" :)))

Gravitational Wave Gastronomy:
David I. Dunsky, Anish Ghoshal, Hitoshi Murayama, Yuki Sakakihara, Graham White
The symmetry breaking of grand unified gauge groups in the early Universe often leaves behind relic topological defects such as cosmic strings, domain walls, or monopoles. For some symmetry breaking chains, hybrid defects can form where cosmic strings attach to domain walls or monopoles attach to strings. In general, such hybrid defects are unstable, with one defect "eating" the other via the conversion of its rest mass into the other's kinetic energy and subsequently decaying via gravitational waves. In this work, we determine the gravitational wave spectrum from 1) the destruction of a cosmic string network by the nucleation of monopoles which cut up and "eat" the strings, 2) the collapse and decay of a monopole-string network by strings that "eat" the monopoles, 3) the destruction of a domain wall network by the nucleation of string-bounded holes on the wall that expand and "eat" the wall, and 4) the collapse and decay of a string-bounded wall network by walls that "eat" the strings. We call the gravitational wave signals produced from the "eating" of one topological defect by another gravitational wave gastronomy. We find that the four gravitational wave gastronomy signals considered yield unique spectra that can be used to narrow down the SO(10) symmetry breaking chain to the Standard Model and the scales of symmetry breaking associated with the consumed topological defects. Moreover, the systems we consider are unlikely to have a residual monopole or domain wall problem.
Comments: 34 pages, 17 figures
квадратная птица Владислав

Новый эксперимент в DESY по изучению непертурбативных эффектов в КЭД

LUXE: A new experiment to study non-perturbative QED:
Louis Helary
Laser Und XFEL Experiment (LUXE), is a new High Energy and Laser Physics experiment planned to be installed in DESY. It will study the interactions of a very-intense Laser beam with the high-energy, high-quality electron beams from the European XFEL accelerator, to measure characteristics of non-perturbative quantum electrodynamics.
Comments: 9 pages, 5 figures, 1 table, proceedings of European Physical Society Conference on High Energy Physics 2021
лошадь, диаграмма, Фейнман

ЯМР и молекулярная динамика

Труд на 60 страниц!

Interpreting NMR dynamic parameters via the separation of reorientational motion in MD simulation:
Albert A. Smith
Reorientational dynamics-motion defined by changes in the direction of a vector or tensor-determine relaxation behavior in nuclear magnetic resonance (NMR). However, if multiple processes exist that result in reorientation, then analyzing the net effects becomes a complex task, so that one ideally would separate those motions to simplify analysis. The model-free and two-step approaches have established the separability of the total correlation function of reorientation motion into contributions from statistically independent motions. Separability has been used to justify the analysis of experimental relaxation rate constants by fitting data to a total correlation function resulting from the product of two or three individual correlation functions, each representing an independent motion. The resulting parameters are used to describe motion in the molecule, but if multiple internal motions are present, interpreting those parameters is not trivial. We suggest an alternative approach: quantitative and timescale-specific comparison of experiment and simulation, as previously established using the detector analysis. This is followed by separation of simulated correlation functions into independent motions, and timescale-specific parameterization of the results, such that one may determine how each motion contributes to experimental parameters. We establish protocols for the separation of the correlation function into components using coordinates from molecular dynamics simulation. Separation is achieved by defining a series of frames, where the frames iteratively split the total motion into contributions from motion within each frame and of each frame. Then timescale specific parameters (e.g. detector responses) describing the total motion may be interpreted in terms of the timescale-specific parameterization of the individual motions.
Comments: 60 pages, 8 figures
лошадь, диаграмма, Фейнман

Позавчерашние чижики с бонусом

Чижик номер раз, прямо напротив того места, где я встретил ласку (естественно, я заходил туда ее проведать но нет:)):

DSC_6251_corr.jpg © qedqed.iMGSRC.RU

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