Search Results for author: Uros Seljak

Found 23 papers, 8 papers with code

Deterministic Langevin Unconstrained Optimization with Normalizing Flows

no code implementations1 Oct 2023 James M. Sullivan, Uros Seljak

We introduce a global, gradient-free surrogate optimization strategy for expensive black-box functions inspired by the Fokker-Planck and Langevin equations.

Active Learning Bayesian Optimization +1

Multiscale Flow for Robust and Optimal Cosmological Analysis

no code implementations7 Jun 2023 Biwei Dai, Uros Seljak

We propose Multiscale Flow, a generative Normalizing Flow that creates samples and models the field-level likelihood of two-dimensional cosmological data such as weak lensing.

Dimensionality Reduction

Deterministic Langevin Monte Carlo with Normalizing Flows for Bayesian Inference

no code implementations27 May 2022 Richard D. P. Grumitt, Biwei Dai, Uros Seljak

We propose a general purpose Bayesian inference algorithm for expensive likelihoods, replacing the stochastic term in the Langevin equation with a deterministic density gradient term.

Bayesian Inference

Translation and Rotation Equivariant Normalizing Flow (TRENF) for Optimal Cosmological Analysis

no code implementations10 Feb 2022 Biwei Dai, Uros Seljak

TRENF is also a generative model of the data, and we show that TRENF samples agree well with the N-body simulations it trained on, and that the inverse mapping of the data agrees well with a Gaussian white noise both visually and on various summary statistics: when this is perfectly achieved the resulting p(x|y) likelihood analysis becomes optimal.

Translation

Unsupervised in-distribution anomaly detection of new physics through conditional density estimation

no code implementations21 Dec 2020 George Stein, Uros Seljak, Biwei Dai

Anomaly detection is a key application of machine learning, but is generally focused on the detection of outlying samples in the low probability density regions of data.

Anomaly Detection Density Estimation

FlowPM: Distributed TensorFlow Implementation of the FastPM Cosmological N-body Solver

2 code implementations22 Oct 2020 Chirag Modi, Francois Lanusse, Uros Seljak

We present FlowPM, a Particle-Mesh (PM) cosmological N-body code implemented in Mesh-TensorFlow for GPU-accelerated, distributed, and differentiable simulations.

Cosmology and Nongalactic Astrophysics Instrumentation and Methods for Astrophysics

Learning effective physical laws for generating cosmological hydrodynamics with Lagrangian Deep Learning

no code implementations6 Oct 2020 Biwei Dai, Uros Seljak

In this work we propose Lagrangian Deep Learning (LDL) for this purpose, applying it to learn outputs of cosmological hydrodynamical simulations.

Sliced Iterative Normalizing Flows

2 code implementations ICML Workshop INNF 2021 Biwei Dai, Uros Seljak

We develop an iterative (greedy) deep learning (DL) algorithm which is able to transform an arbitrary probability distribution function (PDF) into the target PDF.

Density Estimation Image Generation +1

Generative Learning of Counterfactual for Synthetic Control Applications in Econometrics

no code implementations16 Oct 2019 Chirag Modi, Uros Seljak

We combine this Gaussian prior with the data likelihood given by the pre-treatment data of the single unit, to obtain the synthetic prediction of the unit post-treatment, which minimizes the error variance of synthetic prediction.

counterfactual Econometrics +1

Posterior inference unchained with EL_2O

1 code implementation14 Jan 2019 Uros Seljak, Byeonghee Yu

Statistical inference of analytically non-tractable posteriors is a difficult problem because of marginalization of correlated variables and stochastic methods such as MCMC and VI are commonly used.

Clustering

Disconnected Covariance of 2-point Functions in Large-Scale Structure

1 code implementation14 Nov 2018 Yin Li, Sukhdeep Singh, Byeonghee Yu, Yu Feng, Uros Seljak

We verify the analytic covariance against the sample covariance from the galaxy mock simulations in two test cases: (1) the power spectrum multipole covariance, and (2) the joint covariance of the projected correlation function and the correlation function multipoles.

Cosmology and Nongalactic Astrophysics

The Simons Observatory: Science goals and forecasts

1 code implementation22 Aug 2018 The Simons Observatory Collaboration, Peter Ade, James Aguirre, Zeeshan Ahmed, Simone Aiola, Aamir Ali, David Alonso, Marcelo A. Alvarez, Kam Arnold, Peter Ashton, Jason Austermann, Humna Awan, Carlo Baccigalupi, Taylor Baildon, Darcy Barron, Nick Battaglia, Richard Battye, Eric Baxter, Andrew Bazarko, James A. Beall, Rachel Bean, Dominic Beck, Shawn Beckman, Benjamin Beringue, Federico Bianchini, Steven Boada, David Boettger, J. Richard Bond, Julian Borrill, Michael L. Brown, Sarah Marie Bruno, Sean Bryan, Erminia Calabrese, Victoria Calafut, Paolo Calisse, Julien Carron, Anthony Challinor, Grace Chesmore, Yuji Chinone, Jens Chluba, Hsiao-Mei Sherry Cho, Steve Choi, Gabriele Coppi, Nicholas F. Cothard, Kevin Coughlin, Devin Crichton, Kevin D. Crowley, Kevin T. Crowley, Ari Cukierman, John M. D'Ewart, Rolando Dünner, Tijmen de Haan, Mark Devlin, Simon Dicker, Joy Didier, Matt Dobbs, Bradley Dober, Cody J. Duell, Shannon Duff, Adri Duivenvoorden, Jo Dunkley, John Dusatko, Josquin Errard, Giulio Fabbian, Stephen Feeney, Simone Ferraro, Pedro Fluxà, Katherine Freese, Josef C. Frisch, Andrei Frolov, George Fuller, Brittany Fuzia, Nicholas Galitzki, Patricio A. Gallardo, Jose Tomas Galvez Ghersi, Jiansong Gao, Eric Gawiser, Martina Gerbino, Vera Gluscevic, Neil Goeckner-Wald, Joseph Golec, Sam Gordon, Megan Gralla, Daniel Green, Arpi Grigorian, John Groh, Chris Groppi, Yilun Guan, Jon E. Gudmundsson, Dongwon Han, Peter Hargrave, Masaya Hasegawa, Matthew Hasselfield, Makoto Hattori, Victor Haynes, Masashi Hazumi, Yizhou He, Erin Healy, Shawn W. Henderson, Carlos Hervias-Caimapo, Charles A. Hill, J. Colin Hill, Gene Hilton, Matt Hilton, Adam D. Hincks, Gary Hinshaw, Renée Hložek, Shirley Ho, Shuay-Pwu Patty Ho, Logan Howe, Zhiqi Huang, Johannes Hubmayr, Kevin Huffenberger, John P. Hughes, Anna Ijjas, Margaret Ikape, Kent Irwin, Andrew H. Jaffe, Bhuvnesh Jain, Oliver Jeong, Daisuke Kaneko, Ethan D. Karpel, Nobuhiko Katayama, Brian Keating, Sarah S. Kernasovskiy, Reijo Keskitalo, Theodore Kisner, Kenji Kiuchi, Jeff Klein, Kenda Knowles, Brian Koopman, Arthur Kosowsky, Nicoletta Krachmalnicoff, Stephen E. Kuenstner, Chao-Lin Kuo, Akito Kusaka, Jacob Lashner, Adrian Lee, Eunseong Lee, David Leon, Jason S. -Y. Leung, Antony Lewis, Yaqiong Li, Zack Li, Michele Limon, Eric Linder, Carlos Lopez-Caraballo, Thibaut Louis, Lindsay Lowry, Marius Lungu, Mathew Madhavacheril, Daisy Mak, Felipe Maldonado, Hamdi Mani, Ben Mates, Frederick Matsuda, Loïc Maurin, Phil Mauskopf, Andrew May, Nialh McCallum, Chris McKenney, Jeff McMahon, P. Daniel Meerburg, Joel Meyers, Amber Miller, Mark Mirmelstein, Kavilan Moodley, Moritz Munchmeyer, Charles Munson, Sigurd Naess, Federico Nati, Martin Navaroli, Laura Newburgh, Ho Nam Nguyen, Michael Niemack, Haruki Nishino, John Orlowski-Scherer, Lyman Page, Bruce Partridge, Julien Peloton, Francesca Perrotta, Lucio Piccirillo, Giampaolo Pisano, Davide Poletti, Roberto Puddu, Giuseppe Puglisi, Chris Raum, Christian L. Reichardt, Mathieu Remazeilles, Yoel Rephaeli, Dominik Riechers, Felipe Rojas, Anirban Roy, Sharon Sadeh, Yuki Sakurai, Maria Salatino, Mayuri Sathyanarayana Rao, Emmanuel Schaan, Marcel Schmittfull, Neelima Sehgal, Joseph Seibert, Uros Seljak, Blake Sherwin, Meir Shimon, Carlos Sierra, Jonathan Sievers, Precious Sikhosana, Maximiliano Silva-Feaver, Sara M. Simon, Adrian Sinclair, Praween Siritanasak, Kendrick Smith, Stephen R. Smith, David Spergel, Suzanne T. Staggs, George Stein, Jason R. Stevens, Radek Stompor, Aritoki Suzuki, Osamu Tajima, Satoru Takakura, Grant Teply, Daniel B. Thomas, Ben Thorne, Robert Thornton, Hy Trac, Calvin Tsai, Carole Tucker, Joel Ullom, Sunny Vagnozzi, Alexander van Engelen, Jeff Van Lanen, Daniel D. Van Winkle, Eve M. Vavagiakis, Clara Vergès, Michael Vissers, Kasey Wagoner, Samantha Walker, Jon Ward, Ben Westbrook, Nathan Whitehorn, Jason Williams, Joel Williams, Edward J. Wollack, Zhilei Xu, Byeonghee Yu, Cyndia Yu, Fernando Zago, Hezi Zhang, Ningfeng Zhu

With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio.

Cosmology and Nongalactic Astrophysics

Cosmological Reconstruction From Galaxy Light: Neural Network Based Light-Matter Connection

no code implementations6 May 2018 Chirag Modi, Yu Feng, Uros Seljak

Our method relies on following the gradients of forward model and since the standard way to identify halos is non-differentiable and results in a discrete sample of objects, we propose a framework to model the halo position and mass field starting from the non-linear matter field using Neural Networks.

Cosmology and Nongalactic Astrophysics

nbodykit: an open-source, massively parallel toolkit for large-scale structure

2 code implementations15 Dec 2017 Nick Hand, Yu Feng, Florian Beutler, Yin Li, Chirag Modi, Uros Seljak, Zachary Slepian

The package is extensively documented at http://nbodykit. readthedocs. io, which also includes an interactive set of example recipes for new users to explore.

Instrumentation and Methods for Astrophysics Cosmology and Nongalactic Astrophysics

An optimal FFT-based anisotropic power spectrum estimator

no code implementations7 Apr 2017 Nick Hand, Yin Li, Zachary Slepian, Uros Seljak

Here, we present a faster, optimal means of using FFTs for this measurement.

Cosmology and Nongalactic Astrophysics

Intrinsic alignment-lensing interference as a contaminant of cosmic shear

no code implementations10 Jun 2004 Christopher M. Hirata, Uros Seljak

The first model predicts a gravitational-intrinsic (GI) correlation that can be much greater than the intrinsic-intrinsic (II) correlation for broad redshift distributions, and that remains when galaxies pairs at similar redshifts are rejected.

astro-ph

The Sunyaev-Zel'dovich angular power spectrum as a probe of cosmological parameters

1 code implementation27 May 2002 Eiichiro Komatsu, Uros Seljak

It receives a dominant contribution from cluster region between 20-40% of the virial radius and is thus insensitive to the poorly known gas physics in the cluster centre, such as cooling or (pre)heating.

astro-ph

CMBFAST for spatially closed universes

no code implementations11 Nov 1999 Matias Zaldarriaga, Uros Seljak

We extend the cosmological linear perturbation theory code CMBFAST to closed geometries.

astro-ph

Gravitational Lensing Effect on Cosmic Microwave Background Polarization

no code implementations13 Mar 1998 Matias Zaldarriaga, Uros Seljak

As in the case of temperature spectrum gravitational lensing leads to smoothing of narrow features and enhancement of power on the damping tail of the power spectrum.

astro-ph

A Complete Treatment of CMB Anisotropies in a FRW Universe

no code implementations9 Sep 1997 Wayne Hu, Uros Seljak, Martin White, Matias Zaldarriaga

We generalize the total angular momentum method for computing Cosmic Microwave Background anisotropies to Friedman-Robertson-Walker (FRW) spaces with arbitrary geometries.

astro-ph

A Line of Sight Approach to Cosmic Microwave Background Anisotropies

no code implementations8 Mar 1996 Uros Seljak, Matias Zaldarriaga

The source term can be expressed in terms of photon, baryon and metric perturbations, all of which can be calculated using a small number of differential equations.

astro-ph

GRAVITATIONAL LENSING EFFECT ON COSMIC MICROWAVE BACKGROUND ANISOTROPIES: A POWER SPECTRUM APPROACH

no code implementations23 May 1995 Uros Seljak

The effect of gravitational lensing on cosmic microwave background (CMB) anisotropies is investigated using the power spectrum approach.

astro-ph General Relativity and Quantum Cosmology

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