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相关论文: Approximating photo-$z$ PDFs for large surveys

200 篇论文

A precise measurement of photometric redshifts (photo-z) is key for the success of modern photometric galaxy surveys. Machine learning (ML) methods show great promise in this context, but suffer from covariate shift (CS) in training sets…

宇宙学与河外天体物理 · 物理学 2025-08-19 Chiara Moretti , Maximilian Autenrieth , Riccardo Serra , Roberto Trotta , David A. van Dyk , Andrei Mesinger

We present a new regression model for the determination of parton distribution functions (PDF) using techniques inspired from deep learning projects. In the context of the NNPDF methodology, we implement a new efficient computing framework…

高能物理 - 唯象学 · 物理学 2019-09-04 Stefano Carrazza , Juan Cruz-Martinez

We present an end-to-end image compression system based on compressive sensing. The presented system integrates the conventional scheme of compressive sampling and reconstruction with quantization and entropy coding. The compression…

计算机视觉与模式识别 · 计算机科学 2020-01-22 Xin Yuan , Raziel Haimi-Cohen

Automatic summarization is the process of reducing a text document in order to generate a summary that retains the most important points of the original document. In this work, we study two problems - i) summarizing a text document as set…

信息检索 · 计算机科学 2024-06-04 Jayaprakash Sundararaj

We derive the sampling probability density function (pdf) of an ideal localized random electromagnetic field, its amplitude and intensity in an electromagnetic environment that is quasi-statically time-varying statistically homogeneous or…

介观与纳米尺度物理 · 物理学 2015-05-13 L. R. Arnaut

The time evolution of the probability density function (PDF) of the mass density is formulated and solved for systems in free-fall using a simple appoximate function for the collapse of a sphere. We demonstrate that a pressure-free collapse…

星系天体物理 · 物理学 2015-06-17 Philipp Girichidis , Lukas Konstandin , Anthony P. Whitworth , Ralf S. Klessen

Studies of the distribution and evolution of galaxies are of fundamental importance to modern cosmology; these studies, however, are hampered by the complexity of the competing effects of spectral and density evolution. Constructing a…

天体物理学 · 物理学 2009-10-31 R. J. Brunner , A. J. Connolly , A. S. Szalay

Photometric redshifts (photo-$z$'s) will be crucial for studies of galaxy evolution, large-scale structure, and transients with the Nancy Grace Roman Space Telescope. Deep learning methods leverage pixel-level information from ground-based…

天体物理仪器与方法 · 物理学 2026-05-14 Ashod Khederlarian , Brett H. Andrews , Jeffrey A. Newman , Tianqing Zhang , Biprateep Dey

We introduce an adaptive sampling method for the Deep Ritz method aimed at solving partial differential equations (PDEs). Two deep neural networks are used. One network is employed to approximate the solution of PDEs, while the other one is…

机器学习 · 计算机科学 2023-10-31 Xiaoliang Wan , Tao Zhou , Yuancheng Zhou

We demonstrate that the design of the Sloan Digital Sky Survey (SDSS) filter system and the quality of the SDSS imaging data are sufficient for determining accurate and precise photometric redshifts (``photo-z''s) of quasars. Using a sample…

We present a study of photometric redshift performance for galaxies and active galactic nuclei detected in deep radio continuum surveys. Using two multi-wavelength datasets, over the NOAO Deep Wide Field Survey Bo\"otes and COSMOS fields,…

Context: With the advancement of solar physics research, next-generation solar space missions and ground-based telescopes face significant challenges in efficiently transmitting and/or storing large-scale observational data. Aims: We…

天体物理仪器与方法 · 物理学 2025-10-27 Zedong Liu , Song Tan , Alexander Warmuth , Frédéric Schuller , Yun Hong , Wenjing Huang , Yida Gu , Bojing Zhu , Guangming Tan , Dingwen Tao

Pattern-matching-based document-compression systems (e.g. for faxing) rely on finding a small set of patterns that can be used to represent all of the ink in the document. Finding an optimal set of patterns is NP-hard; previous compression…

数据结构与算法 · 计算机科学 2016-01-19 Qin Zhang , John Danskin , Neal Young

The accurate estimation of photometric redshifts plays a crucial role in accomplishing science objectives of the large survey projects. The template-fitting and machine learning are the two main types of methods applied currently. Based on…

We present redshift probability distributions for galaxies in the SDSS DR8 imaging data. We used the nearest-neighbor weighting algorithm presented in Lima et al. 2008 and Cunha et al. 2009 to derive the ensemble redshift distribution N(z),…

宇宙学与河外天体物理 · 物理学 2015-05-30 Erin S. Sheldon , Carlos Cunha , Rachel Mandelbaum , J. Brinkmann , Benjamin A. Weaver

In a companion paper, we proposed combining large numbers of "fuzzy archetypes" with Self-Organizing Maps (SOMs) to derive photometric redshifts in a data-driven way. In this paper, we investigate the performance of several sampling…

宇宙学与河外天体物理 · 物理学 2015-10-29 Joshua S. Speagle , Daniel J. Eisenstein

Fant\^omas is a C++ toolkit for exploring the parametrization dependence of parton distribution functions (PDFs) and other correlator functions in quantum chromodynamics (QCD). Fant\^omas facilitates the generation of adaptable polynomial…

高能物理 - 唯象学 · 物理学 2025-08-01 Lucas Kotz , Aurore Courtoy , T. J. Hobbs , Pavel Nadolsky , Fredrick Olness , Maximiliano Ponce-Chavez , Varada Purohit

We describe a method for constructing mock galaxy catalogues which are well suited for use in conjunction with large photometric surveys. We use the semi-analytic galaxy formation model of Bower et al. implemented in the Millennium…

天体物理学 · 物理学 2009-11-13 Yan-Chuan Cai , Raul E. Angulo , Carlton M. Baugh , Shaun Cole , Carlos S. Frenk , Adrian Jenkins

Our goal is to develop and test a novel methodology to compute accurate close pair fractions with photometric redshifts. We improve the current methodologies to estimate the merger fraction f_m from photometric redshifts by (i) using the…