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We present a further development of a method for accelerating the calculation of CMB power spectra, matter power spectra and likelihood functions for use in cosmological Bayesian inference. The algorithm, called {\sc CosmoNet}, is based on…

Astrophysics · Physics 2009-11-13 T. Auld , M. Bridges , M. P. Hobson

Upcoming large redshift surveys potentially allow precision measurements of the galaxy power spectrum. To accurately measure P(k) on the largest scales, comparable to the depth of the survey, it is crucial that finite volume effects are…

Astrophysics · Physics 2016-01-27 Max Tegmark

We present DeepCHART (Deep learning for Cosmological Heterogeneity and Astrophysical Reconstruction via Tomography), a deep learning framework designed to reconstruct the three-dimensional dark matter density field at redshift $z=2.5$ from…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Soumak Maitra , Matteo Viel , Girish Kulkarni

Many of the most exciting questions in astrophysics and cosmology, including the majority of observational probes of dark energy, rely on an understanding of the nonlinear regime of structure formation. In order to fully exploit the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-13 Earl Lawrence , Katrin Heitmann , Martin White , David Higdon , Christian Wagner , Salman Habib , Brian Williams

Computing pseudospectra of non-normal matrices is essential for understanding the stability and transient behavior of dynamical systems. Such analysis is critical in applications including fluid dynamics, control systems, and differential…

Numerical Analysis · Mathematics 2026-05-07 Amit Punia , Rakesh Kumar , Madan Lal

In a previous paper (part I), the mathematical properties of the cosmic microwave background radiation power spectrum which presents oscillations were discussed. Here, we discuss the physical interpretation: a power spectrum with…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-28 Martin Lopez-Corredoira

21cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Adrian Liu , Max Tegmark

Potential features in the primordial power spectrum have been searched for in galaxy surveys in recent years since these features can assist in understanding the nature of inflation. The null detection to date suggests that any such…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-01 Yuhao Li , Hong-Ming Zhu , Baojiu Li

We have developed a fast method for predicting the angular power spectrum, C_l, of the cosmic microwave background given cosmological parameters and a primordial power spectrum of perturbations. After pre--computing the radiation…

Astrophysics · Physics 2009-11-07 Manoj Kaplinghat , Lloyd Knox , Constantinos Skordis

The next generation of weak lensing surveys will measure the matter distribution of the local Universe with unprecedented precision, allowing the resolution of non-Gaussian features of the convergence field. This encourages the use of…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-17 Dominik Zürcher , Janis Fluri , Virginia Ajani , Silvan Fischbacher , Alexandre Refregier , Tomasz Kacprzak

We consider cosmological applications of galaxy number density correlations to be inferred from future deep and wide multi-band optical surveys. We mostly focus on very large scales as a probe of possible features in the primordial power…

Astrophysics · Physics 2009-11-13 Hu Zhan , Lloyd Knox , J. Anthony Tyson , Vera Margoniner

Any theory invoked to explain cosmic acceleration predicts consistency relations between the expansion history, structure growth, and all related observables. Currently there exist high-quality measurements of the expansion history from…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 R. Ali Vanderveld , Michael J. Mortonson , Wayne Hu , Tim Eifler

We use an ensemble of N-body simulations of the currently favoured (concordance) cosmological model to measure the amount of information contained in the non-linear matter power spectrum about the amplitude of the initial power spectrum.…

Astrophysics · Physics 2009-11-10 C. D. Rimes , A. J. S. Hamilton

We investigate the impact of a common approximation on weak lensing power spectra: the use of single-epoch matter power spectra in integrals over redshift. We disentangle this from the closely connected Limber's approximation. We derive the…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 Lucia F. de la Bella , Nicolas Tessore , Sarah Bridle

Large language models (LLMs) have shown great potential in code-related tasks, yet open-source models lag behind their closed-source counterparts. To bridge this performance gap, existing methods generate vast amounts of synthetic data for…

Computation and Language · Computer Science 2024-08-06 Weijie Lv , Xuan Xia , Sheng-Jun Huang

Fast and accurate computations of the power spectrum of cosmic microwave background fluctuations are essential for comparing current and upcoming data sets with the large parameter space of viable cosmological models. The most efficient…

Astrophysics · Physics 2007-05-23 Arthur Kosowsky

We use numerical simulations of ray tracing through N-body simulations to investigate weak lensing by large-scale structure. These are needed for testing the analytic predictions of two-point correlators, to set error estimates on them and…

Astrophysics · Physics 2007-05-23 Bhuvnesh Jain , Uros Seljak , Simon White

We propose a novel bias-free method for reconstructing the power spectrum of the weak lensing deflection field from cosmic microwave background (CMB) observations. The proposed method is in contrast to the standard method of CMB lensing…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-30 Blake D. Sherwin , Sudeep Das

We allow for nonlinear effects in the likelihood analysis of peculiar velocities, and obtain ~35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear…

Astrophysics · Physics 2009-11-06 A. Dekel , A. Eldar , L. Silberman , I. Zehavi

We present a new method to calculate formation of cosmological structure in the Newtonian limit. The method is based on Lagrangian perturbation theory plus two key theoretical extensions. One advance involves identifying and fixing a…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-15 Sharvari Nadkarni-Ghosh , David F. Chernoff