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A hybrid Eulerian-Lagrangian method is proposed to simulate passive scalar transport on arbitrary shape interface. In this method, interface deformation is tracked by an Eulerian method while the transport of the passive scalar on the…

Computational Physics · Physics 2023-04-20 Yu Fan , Yujie Zhu , Xiaoliang Li , Xiangyu Hu , Nikolaus A. Adams

Lagrangian data assimilation is a complex problem in oceanic and atmospheric modeling. Tracking drifters in large-scale geophysical flows can involve uncertainty in drifter location, complex inertial effects, and other factors which make…

Fluid Dynamics · Physics 2019-01-30 Kristy L. Schlueter-Kuck , John O. Dabiri

Dual decomposition approaches in nonconvex optimization may suffer from a duality gap. This poses a challenge when applying them directly to nonconvex problems such as MAP-inference in a Markov random field (MRF) with continuous state…

Optimization and Control · Mathematics 2022-05-17 Hartmut Bauermeister , Emanuel Laude , Thomas Möllenhoff , Michael Moeller , Daniel Cremers

We use gauge-invariant cosmological perturbation theory to calculate the displacement field that sets the initial conditions for $N$-body simulations. Using first and second-order fully relativistic perturbation theory in the…

General Relativity and Quantum Cosmology · Physics 2016-03-02 Adam J. Christopherson , Juan Carlos Hidalgo , Cornelius Rampf , Karim A. Malik

We present a novel and remarkably simple formulation of degenerate higher-order scalar-tensor (DHOST) theories whose Lagrangian is quadratic in second derivatives of some scalar field. Using disformal transformations of the metric, we…

General Relativity and Quantum Cosmology · Physics 2021-04-21 David Langlois , Karim Noui , Hugo Roussille

Estimating uncertainty in deep learning models is critical for reliable decision-making in high-stakes applications such as medical imaging. Prior research has established that the difference between an input sample and its reconstructed…

Machine Learning · Computer Science 2026-01-28 Xinran Xu , Li Rong Wang , Xiuyi Fan

The measurement of cosmological parameters is investigated in a representation of the least-action method that uses a redshift-space dataset to simultaneously constrain the real-space fields $\delta$,$\b v$. This method is robust in…

Astrophysics · Physics 2009-10-31 Mikel Susperregi

Higher order theories of gravity have recently attracted a lot of interest as alternative candidates to explain the observed cosmic acceleration without the need of introducing any scalar field. A critical ingredient is the choice of the…

Astrophysics · Physics 2009-11-10 S. Capozziello , V. F. Cardone , A. Troisi

21 cm cosmology is a promising new probe of the evolution of visible matter in our universe, especially during the poorly-constrained Cosmic Dawn and Epoch of Reionization. However, in order to separate the 21 cm signal from bright…

We apply an iterative reconstruction method to galaxy mocks in redshift space obtained from $N$-body simulations. Comparing the two-point correlation functions for the reconstructed density field, we find that although the performance is…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 Ryuichiro Hada , Daniel J. Eisenstein

Strongly gravitational lensing systems (SGL) encodes cosmology information in source/lens distance ratios $\mathcal{D}_{\rm obs}=\mathcal{D}_{\rm ls}/\mathcal{D}_{\rm s}$, which can be used to precisely constrain cosmological parameters. In…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-05 Tonghua Liu , Shuo Cao , Jia Zhang , Shuaibo Geng , Yuting Liu , Xuan Ji , Zong-Hong Zhu

Approximations to the exact solutions for gravitational instability in the expanding Universe are extremely useful for understanding the evolution of large--scale structure. We report on a series of tests of Newtonian Lagrangian…

Astrophysics · Physics 2007-05-23 T. Buchert , A. L. Melott , A. G. Weiss

The image subtraction method is a powerful tool to analyze the light variations in crowded fields. This method is able to achieve a nearly optimal differential photometry, even in very dense regions. However, image subtraction is not…

Astrophysics · Physics 2007-05-23 C. Alard

We address the problem to infer physical material parameters and boundary conditions from the observed motion of a homogeneous deformable object via the solution of an inverse problem. Parameters are estimated from potentially unreliable…

Graphics · Computer Science 2022-07-26 Sebastian Weiss , Robert Maier , Rüdiger Westermann , Daniel Cremers , Nils Thuerey

The Lagrangian dynamics of a single fluid element within a self-gravitational matter field is intrinsically non-local due to the presence of the tidal force. This complicates the theoretical investigation of the non-linear evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-23 Xin Wang , Alex Szalay

Modern galaxy surveys demand extensive survey volumes and resolutions surpassing current dark matter-only simulations' capabilities. To address this, many methods employ effective bias models on the dark matter field to approximate object…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-08 Daniel Forero-Sánchez , Francisco-Shu Kitaura , Francesco Sinigaglia , Jose María Coloma-Nadal , Jean-Paul Kneib

A robust algorithm is proposed to reconstruct the spatial support and the Lam\'e parameters of multiple inclusions in a homogeneous background elastic material using a few measurements of the displacement field over a finite collection of…

Numerical Analysis · Mathematics 2017-02-27 Jaejun Yoo , Younghoon Jung , Mikyoung Lim , Jong Chul Ye , Abdul Wahab

Fourth - order gravity theories have received much interest in recent years thanks to their ability to provide an accelerated cosmic expansion in a matter only universe. In these theories, the Lagrangian density of the gravitational field…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-28 Vincenzo F. Cardone , Antonaldo Diaferio , Stefano Camera

We introduce a new approach to prediction in graphical models with latent-shift adaptation, i.e., where source and target environments differ in the distribution of an unobserved confounding latent variable. Previous work has shown that as…

Machine Learning · Statistics 2023-06-26 William I. Walker , Arthur Gretton , Maneesh Sahani

We introduce a new Lagrangian particle tracking algorithm that tracks particles in three dimensions to separations between trajectories approaching contact. The algorithm also detects low Weber number binary collisions that result in…

Fluid Dynamics · Physics 2020-07-15 Reece Vincent Kearney , Gregory Paul Bewley
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