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Lagrangian descriptors reveal the dynamical skeleton governing transport mechanisms of a generic flow. In doing so, they unveil geometrical structures in the phase space that separate regions with different qualitative behavior. This work…

Dynamical Systems · Mathematics 2023-08-22 Alessio Quinci , Gianmario Merisio , Francesco Topputo

A new parameterization for an effective non-linear Lagrangian density of relativistic mean field (RMF) theory is proposed, which is able to provide an excellent description not only for the properties of stable nuclei but also for those far…

Nuclear Theory · Physics 2008-11-26 G. A. Lalazissis , J. König , P. Ring

We study the application of the Augmented Lagrangian Method to the solution of linear ill-posed problems. Previously, linear convergence rates with respect to the Bregman distance have been derived under the classical assumption of a…

Numerical Analysis · Mathematics 2015-06-04 Klaus Frick , Markus Grasmair

Herein, we present a deep-learning technique for reconstructing the dark-matter density field from the redshift-space distribution of dark-matter halos. We built a UNet-architecture neural network and trained it using the COmoving…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-21 Zitong Wang , Feng Shi , Xiaohu Yang , Qingyang Li , Yanming Liu , Xiaoping Li

A novel approach was derived to compute the elastic displacement field from a measured elastic deformation field (i.e., deformation gradient or strain). The method is based on integrating the deformation field using Finite Element…

Materials Science · Physics 2025-12-11 Abdalrhaman Koko , James Marrow , Elsiddig Elmukashfi

A matrix method is formulated in a Lagrangian representation for the solution of the characteristic value problem governing modes of oscillation and instability in a collisionless stellar system. The underlying perturbation equations govern…

Astrophysics · Physics 2009-11-07 Peter O. Vandervoort

We propose an efficient algorithm for sparse signal reconstruction problems. The proposed algorithm is an augmented Lagrangian method based on the dual sparse reconstruction problem. It is efficient when the number of unknown variables is…

Machine Learning · Statistics 2010-10-06 Ryota Tomioka , Masashi Sugiyama

We study the nonlinear gravitational dynamics of a universe filled with a pressureless fluid and a cosmological constant $\Lambda$ in the context of Newtonian gravity, and in the relativistic post-Friedmann approach proposed in paper I [I.…

General Relativity and Quantum Cosmology · Physics 2016-10-26 Cornelius Rampf , Eleonora Villa , Daniele Bertacca , Marco Bruni

We investigate the amount of primordial information that can be reconstructed from spectroscopic galaxy surveys, as well as what sets the noise in reconstruction at low wavenumbers, by studying a simplified universe in which galaxies are…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Matthew McQuinn

Untangling the connection between redshift space coordinates, a velocity measurement, and three dimensional real space coordinates, is a cosmological problem that is often modeled through a linear understanding of the velocity-position…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-05 Emily Tyhurst , Hamsa Padmanabhan , Ue-Li Pen

We present \emph{Unified Lagrangian Perturbation Theory} (ULPT), a perturbative framework for consistently modeling galaxy density fluctuations across real space, redshift space, and post-reconstruction fields. Unlike existing approaches…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-08 Naonori Sugiyama

A new method for the simulation of evolving multi-domains problems has been introduced in previous works (RealIMotion), Florez et al. (2020) and further developed in parallel in the context of isotropic Grain Growth (GG) with no…

Computational Engineering, Finance, and Science · Computer Science 2021-06-23 Sebastian Florez , Karen Alvarado , Marc Bernacki

We introduce a method based on Gaussian process regression to identify discrete variational principles from observed solutions of a field theory. The method is based on the data-based identification of a discrete Lagrangian density. It is a…

Numerical Analysis · Mathematics 2024-07-11 Christian Offen

Most of the information on our cosmos stems from either late-time observations or the imprint of early-time inhomogeneities on the cosmic microwave background. We explore to what extent early modifications of gravity, which become…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-10 Nelson A. Lima , Vanessa Smer-Barreto , Lucas Lombriser

The recently released Quaia quasar catalogue, with its broad redshift range and all-sky coverage, enables unprecedented three-dimensional reconstructions of matter across cosmic time. In this work, we apply the field-level inference…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-03 Adam Andrews , Arthur Loureiro , Jens Jasche , Stuart McAlpine , Guilhem Lavaux , Florent Leclercq

Differential Chromatic Refraction (DCR) is caused by the wavelength dependence of our atmosphere's refractive index, which shifts the apparent positions of stars and galaxies and distorts their shapes depending on their spectral energy…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Jaemyoung Jason Lee , Masao Sako , Richard Kessler , Alex I. Malz , The LSST Dark Energy Science Collaboration

We consider an extended scalar-tensor theory of gravity where the action has two interacting scalar fields, a Brans-Dicke field which makes the effective Newtonian constant a function of coordinates and a Higgs field which has derivative…

General Relativity and Quantum Cosmology · Physics 2021-01-13 Soumya Chakrabarti

This paper proposes an efficient numerical optimization approach for solving dynamic optimal transport (DOT) problems on general smooth surfaces, computing both the quadratic Wasserstein distance and the associated transportation path.…

Optimization and Control · Mathematics 2025-06-11 Liang Chen , Youyicun Lin , Yuxuan Zhou

The gravitational lensing signal from the Cosmic Microwave Background is highly valuable to constrain the growth of the structures in the Universe in a clean and robust manner over a wide range of redshifts. One of the theoretical…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-02 Omar Darwish , Sebastian Belkner , Louis Legrand , Julien Carron , Giulio Fabbian

We demonstrate a systematic implementation of coupling between a scalar field and the geometry of the space (curve, surface, etc.) which carries the field. This naturally gives rise to a feedback mechanism between the field and the…

Pattern Formation and Solitons · Physics 2009-11-10 P. G. Kevrekidis , F. L. Williams , A. R. Bishop , I. G. Kevrekidis , B. A. Malomed