Publications (32)
Differentiable Cosmological Hydrodynamics for Field-Level Inference and High Dimensional Parameter Constraints
Benjamin Horowitz, Zarija Lukic
Hydrodynamical simulations are the most accurate way to model structure formation in the universe, but they often involve a large number of astrophysical parameters modeling subgri…
Maximum A Posteriori Ly-alpha Estimator (MAPLE): Band-power and covariance estimation of the 3D Ly-alpha forest power spectrum
Benjamin Horowitz, Roger de Belsunce, Zarija Lukic
We present a novel maximum a posteriori estimator to jointly estimate band-powers and the covariance of the three-dimensional power spectrum (P3D) of Lyman-alpha forest flux fluctu…
TensorFlow Hydrodynamics Analysis for Ly- Simulations
Jupiter Ding, Benjamin Horowitz, Zarija LukiÄ
We introduce the Python program THALAS (TensorFlow Hydrodynamics Analysis for Lyman-Alpha Simulations), which maps baryon fields (baryon density, temperature, and velocity) to Ly$Î…
HyPhy: Deep Generative Conditional Posterior Mapping of Hydrodynamical Physics
Benjamin Horowitz, Max Dornfest, Zarija LukiÄ +1
Generating large volume hydrodynamical simulations for cosmological observables is a computationally demanding task necessary for next generation observations. In this work, we con…
Plausible Adversarial Attacks on Direct Parameter Inference Models in Astrophysics
Benjamin Horowitz, Peter Melchior
In this abstract we explore the possibility of introducing biases in physical parameter inference models from adversarial-type attacks. In particular, we inject small amplitude sys…
La Silla-QUEST Variability Survey in the Southern Hemisphere
Ellie Hadjiyska, David Rabinowitz, Charles Baltay +6
We describe the La Silla-QUEST (LSQ) Variability Survey. LSQ is a dedicated wide-field synoptic survey in the Southern Hemisphere, focussing on the discovery and study of transient…
Group Theoretical Approach to the Construction of Conformal Field Theories
Benjamin Horowitz
A conformal field theory (CFT) is a quantum field theory which is invariant under conformal transformations; a group action that preserve angles but not necessarily lengths. There…
Efficient Optimal Reconstruction of Linear Fields and Band-powers from Cosmological Data
Benjamin Horowitz, Uros Seljak, Grigor Aslanyan
We present an efficient implementation of Wiener filtering of real-space linear field and optimal quadratic estimator of its power spectrum Band-powers. We first recast the field r…
jFoF: GPU Cluster Finding with Gradient Propagation
Benjamin Horowitz, Adrian E. Bayer
We present jFoF, a fully GPU-native Friends-of-Friends (FoF) halo finder designed for both high-performance simulation analysis and differentiable modeling. Implemented in JAX, jFo…
Joint Cosmic Density Reconstruction from Photometric and Spectroscopic Samples
Benjamin Horowitz, Peter Melchior
We reconstruct the dark matter density field from spatially overlapping spectroscopic and photometric redshift catalogs through a forward modelling approach. Instead of directly in…
NANCY: Next-generation All-sky Near-infrared Community surveY
Jiwon Jesse Han, Arjun Dey, Adrian M. Price-Whelan +206
The Nancy Grace Roman Space Telescope is capable of delivering an unprecedented all-sky, high-spatial resolution, multi-epoch infrared map to the astronomical community. This oppor…
Cosmological constraints from thermal Sunyaev Zeldovich power spectrum revisited
Benjamin Horowitz, Uroš Seljak
Thermal Sunyaev-Zeldovich (tSZ) power spectrum is one of the most sensitive methods to constrain cosmological parameters, scaling as the amplitude . It is determined by the…
Fast, high-fidelity Lyman forests with convolutional neural networks
Peter Harrington, Mustafa Mustafa, Max Dornfest +2
Full-physics cosmological simulations are powerful tools for studying the formation and evolution of structure in the universe but require extreme computational resources. Here, we…
Revisiting Primordial Black Holes Constraints from Ionization History
Benjamin Horowitz
Much attention has been drawn to the recent discoveries by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) of merging intermediate mass black holes. Of part…
Forecasting the power of Higher Order Weak Lensing Statistics with automatically differentiable simulations
Denise Lanzieri, François Lanusse, Chirag Modi +4
We present the Differentiable Lensing Lightcone (DLL), a fully differentiable physical model designed for being used as a forward model in Bayesian inference algorithms requiring a…
diffhydro: Inverse Multiphysics Modeling and Embedded Machine Learning in Astrophysical Flows
Benjamin Horowitz, Zarija LukiÄ, Kentaro Nagamine +1
We present the extension of the differentiable hydrodynamics code, diffhydro, enabling scalable PDE-constrained inference and integrated hybrid physics-ML models for a wide range o…
Reconstructing Small Scale Lenses from the Cosmic Microwave Background Temperature Fluctuations
Benjamin Horowitz, Simone Ferraro, Blake D. Sherwin
Cosmic Microwave Background (CMB) lensing is a powerful probe of the matter distribution in the Universe. The standard quadratic estimator, which is typically used to measure the l…
Constraining the Fluctuating Gunn-Peterson Approximation Using Lyman- Forest Tomography at
Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
The fluctuating Gunn-Peterson approximation (FGPA) is a commonly-used method to generate mock Lyman- (Ly) forest absorption skewers at Cosmic Noon () from the m…
Fast(er)PM and Moving Mesh: JAX-native Geometric Multigrid Methods
Benjamin Horowitz
The paper introduces a JAX-native geometric multigrid framework for solving Poisson equations in particle‑mesh simulations, offering a communication‑avoiding alternative to FFTs on…
MujicÎ: Reconstructing Initial Conditions from Incomplete Redshift Surveys with Projected Optimization
Chenze Dong, Benjamin Horowitz, Adrian E. Bayer +1
In this paper, we introduce MujicÎ (Mapping the Universe with Jax-based Initial Condition ReconstrÎction), an optimization-based framework for reconstructing initial conditions f…
Observational Evidence for Large-Scale Gas Heating in a Galaxy Protocluster at z=2.30
Chenze Dong, Khee-Gan Lee, Metin Ata +2
We report a galaxy protocluster (COSTCO-I) in the COSMOS field, where the Lyman- forest as seen in the CLAMATO IGM tomography survey does not show significant absorpti…
Categories within the Foundation of Mathematics
Benjamin Horowitz
The recent trend in mathematics is towards a framework of abstract mathematical objects, rather than the more concrete approach of explicitly defining elements which objects were t…
Differentiable Stochastic Halo Occupation Distribution
Benjamin Horowitz, ChangHoon Hahn, Francois Lanusse +2
In this work, we demonstrate how differentiable stochastic sampling techniques developed in the context of deep Reinforcement Learning can be used to perform efficient parameter in…
TARDIS Paper II: Synergistic Density Reconstruction from Lyman-alpha Forest and Spectroscopic Galaxy Surveys with Applications to Protoclusters and the Cosmic Web
Benjamin Horowitz, Benjamin Zhang, Khee-Gan Lee +1
In this work we expand upon the Tomographic Absorption Reconstruction and Density Inference Scheme (TARDIS) in order to include multiple tracers while reconstructing matter density…
Generalized Hyperderivative Reed-Solomon Codes
Mahir Bilen Can, Benjamin Horowitz
This article introduces Generalized Hyperderivative Reed-Solomon codes (GHRS codes), which generalize NRT Reed-Solomon codes. Its main results are as follows: 1) every GHRS code is…
TARDIS Paper I: A Constrained Reconstruction Approach to Modeling the z~2.5 Cosmic Web Probed by Lyman-alpha Forest Tomography
Benjamin Horowitz, Khee-Gan Lee, Martin White +2
Recent Lyman- forest tomography measurements of the intergalactic medium (IGM) have revealed a wealth of cosmic structures at high redshift (). In this work, we pres…
BaryonBridge: Stochastic Interpolant Model for Fast Hydrodynamical Simulations
Benjamin Horowitz, Carolina Cuesta-Lazaro, Omar Yehia
Constructing a general-purpose framework for mapping between dark matter simulations and observable hydrodynamical simulation outputs is a long-standing problem in modern astrophys…
Second Data Release of the COSMOS Lyman-alpha Mapping and Tomographic Observation: The First 3D Maps of the Detailed Cosmic Web at 2.05<z<2.55
Benjamin Horowitz, Khee-Gan Lee, Metin Ata +12
We present the second data release of the COSMOS Lyman-Alpha Mapping And Tomography Observations (CLAMATO) Survey conducted with the LRIS spectrograph on the Keck-I telescope. This…
Improved Lyman Alpha Tomography using Optimized Reconstruction with Constraints on Absorption (ORCA)
Zihao Li, Benjamin Horowitz, Zheng Cai
In this work, we propose an improved approach to reconstruct the three-dimensional intergalactic medium from observed Lyman- forest absorption features. We present our new meth…
Alignments Between Galaxies and the Cosmic Web at in the IllustrisTNG Simulations
Benjamin Zhang, Khee-Gan Lee, Alex Krolewski +3
Galaxy formation theories predict that galaxy shapes and angular momenta have non-random alignments with the cosmic web. This leads to so-called intrinsic alignment between pairs o…
Introducing cosmosTNG: simulating galaxy formation with constrained realizations of the COSMOS field
Chris Byrohl, Dylan Nelson, Benjamin Horowitz +2
We introduce the new cosmological simulation project cosmosTNG, a first-of-its-kind suite of constrained galaxy formation simulations for the universe at Cosmic Noon (). c…
The Dependence of Galaxy Properties on the Underlying 3D Matter Density Field at 2.0 < z < 2.5
Rieko Momose, Khee-Gan Lee, Benjamin Horowitz +2
We study the environmental effect of galaxy evolution as a function of the underlying 3D dark matter density for the first time at , in which the underlying matter density…