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Related papers: Ridged Lagrangian Perturbation Theory (RLPT)

200 papers

Many complex physical systems admit natural decomposition into an exactly solvable component and a perturbative correction. Rather than training neural networks to learn complete trajectories from scratch, we introduce Neural Network…

Computational Physics · Physics 2025-12-02 Zhenhao Chen , Mutian Shen , Boris Fain , Zohar Nussinov

The linear perturbation theory of inhomogeneous reionization (LPTR) has been developed as an analytical tool for predicting the global ionized fraction and large-scale power spectrum of ionized density fluctuations during reionization. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-05 Yi Mao , Anson D'Aloisio , Benjamin D. Wandelt , Jun Zhang , Paul R. Shapiro

We examine the Lagrangian divergence of the displacement field, arguably a more natural object than the density in a Lagrangian description of cosmological large-scale structure. This quantity, which we denote \psi, quantifies the…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-17 Mark C. Neyrinck

This paper investigates the use of a sampling-based approach, the RRT*, to reconfigure a 2D set of connected tiles in complex environments, where multiple obstacles might be present. Since the target application is automated building of…

Robotics · Computer Science 2022-10-27 Javier Garcia , Michael Yannuzzi , Peter Kramer , Christian Rieck , Aaron T. Becker

I compute a renormalization group (RG) improvement to the standard beyond-linear-order Eulerian perturbation theory (PT) calculation of the power spectrum of large-scale density fluctuations in the Universe. At z=0, for a power spectrum…

Astrophysics · Physics 2008-11-26 Patrick McDonald

We present a new formulation of Lagrangian perturbation theory which allows accurate predictions of the real- and redshift-space correlation functions of the mass field and dark matter halos. Our formulation involves a non-perturbative…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jordan Carlson , Beth Reid , Martin White

Network pruning is a widely used technique to reduce computation cost and model size for deep neural networks. However, the typical three-stage pipeline significantly increases the overall training time. In this paper, we develop a…

Neural and Evolutionary Computing · Computer Science 2023-04-11 Shanglin Zhou , Mikhail A. Bragin , Lynn Pepin , Deniz Gurevin , Fei Miao , Caiwen Ding

A significant drawback of Lagrangian (particle-tracking) reactive transport models has been their inability to properly simulate interactions between solid and liquid chemical phases, such as dissolution and precipitation reactions. This…

Recent research has emphasized the benefits of accurately reconstructing the initial Lagrangian positions of biased tracers from their positions at a later time, to gain cosmological information. A weighted semi-discrete optimal transport…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-10 Farnik Nikakhtar , Nikhil Padmanabhan , Bruno Lévy , Ravi K. Sheth , Roya Mohayaee

We present the one-loop 2-point function of biased tracers in redshift space computed with Lagrangian perturbation theory, including a full resummation of both long-wavelength (infrared) displacements and associated velocities. The…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Shi-Fan Chen , Zvonimir Vlah , Emanuele Castorina , Martin White

Embedding tables are usually huge in click-through rate (CTR) prediction models. To train and deploy the CTR models efficiently and economically, it is necessary to compress their embedding tables at the training stage. To this end, we…

Machine Learning · Computer Science 2024-08-07 Shiwei Li , Huifeng Guo , Lu Hou , Wei Zhang , Xing Tang , Ruiming Tang , Rui Zhang , Ruixuan Li

Lagrangian displacement field $\Psi$ is the central object in Lagrangian perturbation theory (LPT). LPT is very successful at high redshifts, but it performs poorly at low redshifts due to severe shell crossing. To understand and quantify…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-16 Kwan Chuen Chan

Motion planning problems have been studied by both the robotics and the controls research communities for a long time, and many algorithms have been developed for their solution. Among them, incremental sampling-based motion planning…

Robotics · Computer Science 2012-05-01 Oktay Arslan , Panagiotis Tsiotras

The nonlinear perturbation theory of gravitational instability is extended to include effects of both biasing and redshift-space distortions, which are inevitable in predicting observable quantities in galaxy surveys. The precise…

Astrophysics · Physics 2014-11-18 Takahiko Matsubara

Standard perturbation theory (SPT) for large-scale matter inhomogeneities is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small on all scales; it does not fully account…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Enrico Pajer , Matias Zaldarriaga

We present results showing an improvement of the accuracy of perturbation theory as applied to cosmological structure formation for a useful range of quasilinear scales. The Lagrangian theory of gravitational instability of an Einstein-de…

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

Trajectory optimization of low-thrust perturbed orbit rendezvous is a crucial technology for space missions in low Earth orbits, which is difficult to solve due to its initial value sensitivity, especially when the transfer trajectory has…

Instrumentation and Methods for Astrophysics · Physics 2023-05-03 An-yi Huang , Heng-nian Li

We devise a {\sl non--perturbative} method, called {\sl Parametric Perturbation Theory} (PPT), which is alternative to the ordinary perturbation theory. The method relies on a principle of simplicity for the observable solutions, which are…

High Energy Physics - Phenomenology · Physics 2007-05-23 Paolo Amore

Lagrangian turbulence lies at the core of numerous applied and fundamental problems related to the physics of dispersion and mixing in engineering, bio-fluids, atmosphere, oceans, and astrophysics. Despite exceptional theoretical,…

We develop a new approach to study the nonlinear evolution in the large-scale structure of the Universe both in real space and in redshift space, extending the standard perturbation theory of gravitational instability. Infinite series of…

Astrophysics · Physics 2008-11-26 Takahiko Matsubara