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Understanding the universe in its pristine epoch is crucial in order to obtain a concise comprehension of the late-time universe. Although current data in cosmology are compatible with Gaussian primordial perturbations whose power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-15 Thiago Mergulhão , Florian Beutler , John A. Peacock

In this work, we investigate the quasinormal modes of the Poincar\'e thick brane with a finite extra dimension. Unlike the case with an infinite extra dimension, the gravitational effective potential exhibits three distinct shapes within…

General Relativity and Quantum Cosmology · Physics 2025-01-03 Hai-Long Jia , Wen-Di Guo , Qin Tan , Yu-Xiao Liu

Massive bigravity, a theoretically consistent modification of general relativity with an additional dynamical rank two tensor, successfully describes the observed accelerated expansion of the Universe without a cosmological constant. Recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 Matthew Johnson , Alexandra Terrana

Fourier series multiscale method, a concise and efficient analytical approach for multiscale computation, will be developed out of this series of papers. In the sixth paper, exact analysis of the wave propagation in a beam with rectangular…

Numerical Analysis · Mathematics 2022-08-30 Weiming Sun , Zimao Zhang

We present a method for constructing superoscillatory functions the superoscillatory part of which approximates a given polynomial with arbitrarily small error in a fixed interval. These functions are obtained as the product of the…

Mathematical Physics · Physics 2015-04-21 Ioannis Chremmos , George Fikioris

Recently, complex horizontal patterns of umbral oscillations have been reported, but their physical nature and origin are still not fully understood. Here we show that the two-dimensional patterns of umbral oscillations of slow waves are…

Solar and Stellar Astrophysics · Physics 2024-06-05 Juhyung Kang , Jongchul Chae , Kyuhyoun Cho , Soosang Kang , Eun-Kyung Lim

In the standard big bang model the universe starts in a radiation dominated era, where the gravitational perturbations are described by second order differential equations, which will generally have two orthogonal set of solutions. One is…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-04 Darsh Kodwani , P. Daniel Meerburg , Ue-Li Pen , Xin Wang

The modal dispersion of waveguides often limits integrated photonic devices to operation with a single polarization state. This presents a challenge for sensing and spectroscopy applications, which often require polarization diversity over…

Plasmonic Janus particles, comprising dielectric cores with thin metallic caps, exhibit complex optical properties due to their asymmetric structure. Despite applications in active matter research, their orientation-dependent scattering…

Optics · Physics 2025-07-22 Felix H. Patzschke , Frank Cichos

We compute precise values of quasinormal modes of a massive scalar field in the background of the Schwarzschild-like brane-localised black holes. It is shown that the quasinormal spectrum of the massive field differs qualitatively from that…

General Relativity and Quantum Cosmology · Physics 2024-03-12 Antonina F. Zinhailo

A novel approach towards the spectral analysis of stationary random bivariate signals is proposed. Using the Quaternion Fourier Transform, we introduce a quaternion-valued spectral representation of random bivariate signals seen as…

Methodology · Statistics 2017-11-22 Julien Flamant , Nicolas Le Bihan , Pierre Chainais

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Maresuke Shiraishi

We develop a novel technique through spectral decompositions to study the gravitational perturbations of a black hole, without needing to decouple the linearized field equations into master equations and separate their radial and angular…

General Relativity and Quantum Cosmology · Physics 2023-06-19 Adrian Ka-Wai Chung , Pratik Wagle , Nicolas Yunes

This paper presents a method for reconstructing an acoustic source located in a two-layered medium from multi-frequency phased or phaseless far-field patterns measured on the upper hemisphere. The interface between the two media is assumed…

Numerical Analysis · Mathematics 2024-12-10 Yan Chang , Yukun Guo , Yue Zhao

By applying the dimensionless scheme, we investigate the quasinormal modes and phase transitions analytically for three types of regular black holes. The universal deviations to the first law of mechanics in regular black holes are proved.…

General Relativity and Quantum Cosmology · Physics 2022-05-13 Chen Lan , Yan-Gang Miao , Hao Yang

In even-dimensional Euclidean space for integer powers of the Laplacian greater than or equal to the dimension divided by two, a fundamental solution for the polyharmonic equation has logarithmic behavior. We give two approaches for…

Classical Analysis and ODEs · Mathematics 2012-02-09 Howard S. Cohl

We study how to probe bispectra of stochastic gravitational waves with pulsar timing arrays. The bispectrum is a key to probe the origin of stochastic gravitational waves. In particular, the shape of the bispectrum carries valuable…

General Relativity and Quantum Cosmology · Physics 2019-03-25 Makoto Tsuneto , Asuka Ito , Toshifumi Noumi , Jiro Soda

Primordial Gravitational waves leave polarization imprints on the Cosmic Microwave Background (CMB). In this article, we investigate polarization bispectrum, which is also referred to as the B-mode auto bispectrum, due to a matter bounce…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-17 Rahul Kothari , Debottam Nandi

We investigate the non-Gaussianity of second-order matter density perturbations induced by primordial gravitational waves (GWs). These tensor-induced scalar modes arise from local fluctuations in the GWs energy density, which is quadratic…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Mariam Abdelaziz , Pritha Bari , Sabino Matarrese , Angelo Ricciardone

The simplest inflationary models present us with few observable parameters to discriminate between them. A detection of features in the spectra of primordial density perturbations could provide valuable insights and lead to stringent tests…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-14 J. R. Fergusson , H. F. Gruetjen , E. P. S. Shellard , M. Liguori