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The analysis of the Lyman-alpha forest of absorption lines in quasar spectra has emerged as a potentially powerful technique to constrain the linear matter power spectrum. In most previous work, the amplitude of the ionizing background was…

Astrophysics · Physics 2009-11-11 Adam Lidz , Katrin Heitmann , Lam Hui , Salman Habib , Michael Rauch , Wallace L. W. Sargent

A sample of eight quasars observed at high resolution and signal-to-noise is used to determine the probability distribution function (PDF), the power spectrum, and the correlation function of the transmitted flux in the \lya forest, in…

The Lyman-alpha forest is a portion of the observed light spectrum of distant galactic nuclei which allows us to probe remote regions of the Universe that are otherwise inaccessible. The observed Lyman-alpha forest of a quasar light…

We present a measurement of the Lyman alpha flux probability distribution function (PDF) measured from a set of eight high resolution quasar spectra with emission redshifts at 3.3 < z < 3.8. We carefully study the effect of metal absorption…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 F. Calura , E. Tescari , V. D'Odorico , M. Viel , S. Cristiani , T. -S. Kim , J. S. Bolton

We measure the power spectrum, P_F(k,z), of the transmitted flux in the Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital Sky Survey. This sample is almost two orders of magnitude larger than any previously…

Probability distribution functions (PDFs) of column densities are an established tool to characterize the evolutionary state of interstellar clouds. Using simulations, we show to what degree their determination is affected by noise,…

Instrumentation and Methods for Astrophysics · Physics 2016-05-25 Volker Ossenkopf-Okada , Timea Csengeri , Nicola Schneider , Christoph Federrath , Ralf S. Klessen

We use the probability distribution function (PDF) of the lya forest flux at z=2-3, measured from high-resolution UVES/VLT data, and hydrodynamical simulations to obtain constraints on cosmological parameters and the thermal state of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 M. Viel , J. S. Bolton , M. G. Haehnelt

We study the effect of the non-Gaussianity induced by gravitational evolution upon the statistical properties of absorption in quasar (QSO) spectra. Using the generic hierarchical ansatz and the lognormal approximation we derive the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Dipak Munshi , Peter Coles , Matteo Viel

Weak lensing measurements are starting to provide statistical maps of the distribution of matter in the universe that are increasingly precise and complementary to cosmic microwave background maps. The probability distribution (PDF)…

Astrophysics · Physics 2009-11-10 Tong-Jie Zhang , Ue-Li Pen

Perturbation theory makes it possible to calculate the probability distribution function (PDF) of the large scale density field in the small variance limit. For top hat smoothing and scale-free Gaussian initial fluctuations, the result…

Astrophysics · Physics 2015-06-24 S. Colombi , F. Bernardeau , F. R. Bouchet , L. Hernquist

We explore the effect of applying a non-linear transformation to the Lyman-$\alpha$ forest transmitted flux $F=e^{-\tau}$ and the ability of analytic models to predict the resulting clustering amplitude. Both the large-scale bias of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-10 Xinkang Wang , Andreu Font-Ribera , Uros Seljak

We have proposed a method for measuring weak lensing using the Lyman-alpha forest. Here we estimate the noise expected in weak lensing maps and power spectra for different sets of observational parameters. We find that surveys of the size…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-21 R. Benton Metcalf , Rupert A. C. Croft , Alessandro Romeo

This paper tackles the issue of real-time parametric estimation of a wide class of probability density functions from limited datasets. This type of estimation addresses recent applications that require joint sensing and actuation. The…

Information Theory · Computer Science 2022-03-21 Ahmad A. Masoud

We investigate the possibility of constraining primordial non-Gaussianity using the 3D bispectrum of Ly-alpha forest. The strength of the quadratic non-Gaussian correction to an otherwise Gaussian primordial gravitational field is assumed…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-19 Dhiraj Kumar Hazra , Tapomoy Guha Sarkar

A new and simple statistical approach is performed to calculate the parton distribution functions (PDFs) of the nucleon in terms of light-front kinematic variables. We do not put in any extra arbitrary parameter or corrected term by hand,…

High Energy Physics - Phenomenology · Physics 2009-03-12 Yunhua Zhang , Lijing Shao , Bo-Qiang Ma

Modern analysis on parton distribution functions (PDFs) requires calculations of the log-likelihood functions from thousands of experimental data points, and scans of multi-dimensional parameter space with tens of degrees of freedom. In…

High Energy Physics - Phenomenology · Physics 2022-08-24 DianYu Liu , ChuanLe Sun , Jun Gao

We consider the statistics of light amplitude fluctuations for the propagation of a laser beam subjected to multiple filamentation in an amplified Kerr media, with both linear and nonlinear dissipation. Dissipation arrests the catastrophic…

Chaotic Dynamics · Physics 2010-10-21 Pavel M. Lushnikov , Natalia Vladimirova

The inference of astrophysical and cosmological properties from the Lyman-$\alpha$ forest conventionally relies on summary statistics of the transmission field that carry useful but limited information. We present a deep learning framework…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-11 Parth Nayak , Michael Walther , Daniel Gruen , Sreyas Adiraju

The Ly$\alpha$ forest transmission probability distribution function (PDF) is an established probe of the intergalactic medium (IGM) astrophysics, especially the temperature-density relationship of the IGM. We measure the transmission PDF…

The probability density function (PDF) associated with a given set of samples is approximated by a piecewise-linear polynomial constructed with respect to a binning of the sample space. The kernel functions are a compactly supported basis…

Numerical Analysis · Mathematics 2020-08-04 Giacomo Capodaglio , Max Gunzburger
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