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Weak gravitational lensing is an invaluable tool for understanding fundamental cosmological physics. An unresolved issue in weak lensing cosmology is to accurately reconstruct the lensing convergence $\kappa$ maps from discrete shear…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Yuan Shi , Pengjie Zhang , Zeyang Sun , Yihe Wang

Observations of redshifted Lyman alpha forest absorption in the spectra of quasistellar objects (QSOs) provide a highly sensitive probe of the distribution of gaseous matter in the universe. Over the past two decades optical spectroscopy…

Astrophysics · Physics 2009-10-30 Michael Rauch

Cosmic shear surveys serve as a powerful tool for mapping the underlying matter density field, including non-visible dark matter. A key challenge in cosmic shear surveys is the accurate reconstruction of lensing convergence ($\kappa$) maps…

Instrumentation and Methods for Astrophysics · Physics 2025-11-27 Yuan Shi , Pengjie Zhang , Furen Deng , Shuren Zhou , Hongbo Cai , Ji Yao , Zeyang Sun

[Abridged] We present FLO (From Lines to Over-densities), a new technique to reconstruct the hydrogen density field for the Lya forest lines observed in high resolution QSO spectra. The method is based on the hypothesis that the Lya lines…

Astrophysics · Physics 2009-11-13 F. Saitta , V. D'Odorico , M. Bruscoli , S. Cristiani , P. Monaco , M. Viel

Massive spectroscopic surveys of high-redshift quasars yield large numbers of correlated Lyman {\alpha} absorption spectra that can be used to measure large-scale structure. Simulations of these surveys are required to accurately interpret…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Andreu Font-Ribera , Patrick McDonald , Jordi Miralda-Escudé

The Lyman-$\alpha$ forest opacity fluctuations observed from high-redshift quasar spectra have been proven to be extremely successful in order to probe the late phase of the reionization epoch. For ideal modeling of these opacity…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-28 Barun Maity , Frederick Davies , Prakash Gaikwad

Recently, NIRSpec PRISM/CLEAR observations by JWST have begun providing rest-frame UV continuum measurements of galaxies at $z\gtrsim7$, revealing signatures of Ly$\alpha$ damping-wing (DW) absorption by the intergalactic medium (IGM). We…

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

The 21-cm forest is a promising probe of the Epoch of Reionization. The local state of the intergalactic medium (IGM) is encoded in the spectrum of a background source (radio-loud quasars or gamma ray burst afterglow) by absorption at the…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Benoit Semelin

Upcoming ground-based cosmic microwave background experiments will provide CMB maps with high sensitivity and resolution that can be used for high fidelity lensing reconstruction. However, the sky coverage will be incomplete and the noise…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-11 Mark Mirmelstein , Julien Carron , Antony Lewis

Mapping of the large-scale structure through cosmic time has numerous applications in the studies of cosmology and galaxy evolution. At $z > 2$, the structure can be traced by the neutral intergalactic medium (IGM) by way of observing the…

A convincing physical picture for the Lyman-alpha forest has emerged from simulations and related semi-analytic studies of structure formation models. Observations can be be used in the context of this picture to study cosmology using the…

Astrophysics · Physics 2007-05-23 Rupert Croft , David Weinberg , Neal Katz , Lars Hernquist

We present the first clustering measurement of Strong Blended Lyman $\alpha$ (SBLA) absorption systems by measuring their cross-correlation with the Lyman $\alpha$ forest. SBLAs are a new population of absorbers detected within the Lyman…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-18 Ignasi Pérez-Ràfols , Matthew M. Pieri , Michael Blomqvist , Sean Morrison , Debopam Som , Andrei Cuceu

We derive and numerically implement an algorithm for estimating the 3D power spectrum of the Lyman-$\alpha$ (Ly-$\alpha$) forest flux fluctuations. The algorithm exploits the unique geometry of Ly-$\alpha$ forest data to efficiently measure…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Andreu Font-Ribera , Patrick McDonald , Anže Slosar

The problem of reconstructing an object from the measurements of the light it scatters is common in numerous imaging applications. While the most popular formulations of the problem are based on linearizing the object-light relationship,…

Computer Vision and Pattern Recognition · Computer Science 2017-12-15 Yanting Ma , Hassan Mansour , Dehong Liu , Petros T. Boufounos , Ulugbek S. Kamilov

The existence of galaxy intrinsic clustering severely hampers the weak lensing reconstruction from cosmic magnification. In paper I \citep{Yang2011}, we proposed a minimal variance estimator to overcome this problem. By utilizing the…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Xinjuan Yang , Pengjie Zhang , Jun Zhang , Yu Yu

A simple, yet general, formalism for the optimized linear combination of astrophysical images is constructed and demonstrated. The formalism allows the user to combine multiple undersampled images to provide oversampled output at high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Barnaby Rowe , Christopher Hirata , Jason Rhodes

We present constraints on the amplitude and shape of the matter power spectrum and the density of dark matter within the framework of a standard LambdaCDM model. We use a Markov Chain Monte Carlo approach to combine independent measurements…

Astrophysics · Physics 2008-11-26 J. Lesgourgues , M. Viel , M. G. Haehnelt , R. Massey

Recent advances in diffusion-based Large Restoration Models (LRMs) have significantly improved photo-realistic image restoration by leveraging the internal knowledge embedded within model weights. However, existing LRMs often suffer from…

Computer Vision and Pattern Recognition · Computer Science 2024-10-10 Hang Guo , Tao Dai , Zhihao Ouyang , Taolin Zhang , Yaohua Zha , Bin Chen , Shu-tao Xia

We publicly release a new sample of $34$ medium resolution quasar spectra at $5.77\leq z_{\rm em}\leq6.54$ observed with the Echellette Spectrograph and Imager (ESI) on the Keck telescope. This quasar sample represents an ideal laboratory…

Astrophysics of Galaxies · Physics 2018-09-05 Anna-Christina Eilers , Frederick B. Davies , Joseph F. Hennawi