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We study linear panel regression models in which the unobserved error term is an unknown smooth function of two-way unobserved fixed effects. In standard additive or interactive fixed effect models the individual specific and time specific…

Econometrics · Economics 2022-08-15 Hugo Freeman , Martin Weidner

Post-Double-Lasso is becoming the most popular method for estimating linear regression models with many covariates when the purpose is to obtain an accurate estimate of a parameter of interest, such as an average treatment effect. However,…

Econometrics · Economics 2025-11-27 Sullivan Hué , Sébastien Laurent , Ulrich Aiounou , Emmanuel Flachaire

We measure the filling factor, correlation function, and power spectrum of transmitted flux in a large sample of Lya forest spectra, comprised of 30 Keck HIRES spectra and 23 Keck LRIS spectra. We infer the linear matter power spectrum P(k)…

The Lyman-$\alpha$ forest is a valuable probe of dark matter models featuring a scale-dependent suppression of the power spectrum as compared to $\Lambda$CDM. In this work, we present a new estimator of the Lyman-$\alpha$ flux power…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Mathias Garny , Thomas Konstandin , Laura Sagunski , Sean Tulin

While the Lyman-$\alpha$ (Ly$\alpha$) forest traces the large-scale matter distribution over a wide range of redshift, its three-dimensional (3D) clustering at $z < 2$ has not yet been measured. We investigate the prospects for measuring…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Ting Tan , Huanyuan Shan , Eric Armengaud

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

Weak gravitational lensing is a powerful probe of cosmology, with second-order shear statistics commonly used to constrain parameters such as the matter density $\Omega_\mathrm{m}$ and the clustering amplitude $S_8$. However, parameter…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-26 Niek Wielders , Laila Linke , Pierre A. Burger , Sven Heydenreich , Lucas Porth , Peter Schneider

This paper studies magnetic line defects in the Wilson-Fisher $O(N)$ model. A powerful method to probe the system is to consider mixed two-point functions of the order parameter and the energy operator in the presence of the defect. A…

High Energy Physics - Theory · Physics 2022-12-07 Aleix Gimenez-Grau

Recently, the Lyman-$\alpha$ (Ly$\alpha$) forest flux auto-correlation function has been shown to be sensitive to the mean free path of hydrogen-ionizing photons, $\lambda_{\text{mfp}}$, for simulations at $z \geq 5.4$. Measuring…

We examine the impact of gas pressure on the transverse coherence of high-redshift (2 <= z <= 4) Lyman-alpha forest absorption along neighboring lines of sight that probe the gas Jeans scale (projected separation Delta r <= 500 kpc/h…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Molly S. Peeples , David H. Weinberg , Romeel Davé , Mark A. Fardal , Neal Katz

We present a semi-analytic model for the Lyman-$\alpha$ forest that is inspired by the Halo Model. This model is built on the absorption line decomposition of the forest. Flux correlations are decomposed into those within each absorption…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-10 Vid Iršič , Matthew McQuinn

The Lyman-$\alpha$ forests observed in the spectra of high-redshift quasars can be used as a tracer of the cosmological matter density to study baryon acoustic oscillations (BAO) and the Alcock-Paczynski effect. Extraction of cosmological…

Humans struggle to perceive and interpret high-dimensional data. Therefore, high-dimensional data are often projected into two dimensions for visualization. Many applications benefit from complex nonlinear dimensionality reduction…

Machine Learning · Computer Science 2025-06-11 Olga Ovcharenko , Rita Sevastjanova , Valentina Boeva

In this paper we critically examine predictions of the Lya forest within the standard cold dark matter (SCDM) model, paying particular attention to the low end of the column-density distribution. We show in particular that the width of…

Astrophysics · Physics 2009-10-30 Greg L. Bryan , Marie Machacek , Peter Anninos , Michael L. Norman

We study halo clustering bias with second- and third-order statistics of halo and matter density fields in the MICE Grand Challenge simulation. We verify that two-point correlations deliver reliable estimates of the linear bias parameters…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-19 Julien Bel , Kai Hoffmann , Enrique Gaztañaga

In Lyman-alpha forest measurements it is generally assumed that quasars are mere background light sources which are uncorrelated with the forest. Gravitational lensing of the quasars violates this assumption. This effect leads to a…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-14 Marilena LoVerde , Stefanos Marnerides , Lam Hui , Brice Menard , Adam Lidz

We demonstrate that the lyman alpha forest flux power spectrum of ``randomised'' QSO absorption spectra is comparable in shape and amplitude to the flux power spectrum of the original observed spectra. In the randomised spectra a random…

Astrophysics · Physics 2009-11-10 M. Viel , M. G. Haehnelt , R. F. Carswell , T. -S. Kim

Line-intensity mapping (LIM) is quickly attracting attention as an alternative technique to probe large-scale structure and galaxy formation and evolution at high redshift. LIM one-point statistics are motivated because they provide access…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-06 José Luis Bernal

The two-point correlation function (2PCF) is a cornerstone of precision cosmology, yet its estimation from imaging surveys is vulnerable to contamination and incompleteness arising from imperfect target selection and pipeline-level…

Instrumentation and Methods for Astrophysics · Physics 2026-03-13 Arya Farahi

Dual-tree wavelet decompositions have recently gained much popularity, mainly due to their ability to provide an accurate directional analysis of images combined with a reduced redundancy. When the decomposition of a random process is…

Statistics Theory · Mathematics 2011-08-30 Caroline Chaux , Jean-Christophe Pesquet , Laurent Duval
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