Flatiron Institute

Inductive Biases in Field-level Cosmological Inference from Galaxy Catalogs

Abstract We perform field-level likelihood-free inference of the matter density parameter Ω m from simulated galaxy catalogs using machine learning models with differing inductive biases. Using hydrodynamic simulations from CAMELS, we examine how observable choice and architectur...

Foveated metamers of the early visual system

Abstract The ability of humans to discriminate and identify spatial patterns varies across the visual field, and is generally worse in the periphery than in the fovea. This decline in performance is revealed in many kinds of tasks, from detection to recognition. A parsimonious hy...

Compressing multivariate functions with tree tensor networks

Tensor networks are a compressed format for multi-dimensional data. One dimensional tensor networks—often referred to as tensor trains (TT) or matrix product states (MPS)—are increasingly being used as a numerical Ansatz for continuum functions by ``quantizing’’ the inputs into d...

The First Multi-Messenger Nova: External Shocks, TeV Photons, and Neutrinos in the Next Eruption of T CrB

Abstract T Coronae Borealis is the most compelling anticipated Galactic recurrent nova and one of the best opportunities to test whether nova eruptions can become genuine multi-messenger transients. Recent observational work on classical novae has shown that the GeV γ-ray luminos...

The WEST code for large-scale excited-state materials simulations

We present WEST, an open-source plane-wave pseudopotential code for large-scale excited-state materials simulations, and describe its theoretical foundations, software architecture, and capabilities. WEST implements full-frequency GW, quantum defect embedding theory, the Bethe–Sa...

Identifying Galactic Binary Systems of Neutron Stars and Black Holes with LISA

Abstract The Laser Interferometer Space Antenna (LISA) will detect ∼100 Galactic binary systems comprised of black holes and neutron stars. Distinguishing these binaries from the ∼10 4 double white dwarfs detectable by LISA will be challenging. In the absence of any other informa...

Generalized Nonlinear Bayesian Pulsar Timing with ENTERPRISE

Abstract We use the Bayesian methods in the ENTERPRISE package to examine the fully general parameterization of pulsar timing models in tandem with noise. We investigate four pulsars, PSRs J1600–3053, J2043+1711, J0740+6620, and J1640+2224, through the lens of Bayesian timing. We...

Efficiently emulating distribution functions in gigaparsec volumes for varying cosmological parameters

Abstract We present a new method for emulating the halo mass function (HMF) and other distribution functions in large effective volumes, down to low halo masses, whilst simultaneously modifying large ranges of parameters, for a fraction of the cost of traditional periodic cosmolo...

STAR_Lite: a stellarator designed to experimentally validate non-resonant divertors

The non-resonant divertor (NRD) offers a promising exhaust solution for stellarators, combining topological simplicity with resilience to magnetic field perturbations. To experimentally validate the robustness of NRDs in a quasi-axisymmetric (QA) configuration, we introduce STAR_...

2D theoretically twistable material database

The study of twisted two-dimensional (2D) materials, in which twisting layers create moiré superlattices, has created opportunities for investigating topological phases and strongly correlated physics. The broader potential of a seemingly infinite set of twistable 2D materials re...

Unidirectional flow from continuous broken symmetries

Locally broken symmetries are used across fields to transport matter, particles, and information in preferential directions. Beyond local mechanisms, spatially distributed nonlinearities in crystalline media have enabled nonreciprocal transport, a rectification mechanism that ope...

Neural network–augmented Pfaffian wave-functions for scalable simulations of interacting fermions

Developing accurate numerical methods for strongly interacting fermions is crucial for improving our understanding of various quantum many-body phenomena, especially unconventional superconductivity. Recently, neural quantum states have emerged as a promising approach for studyin...

The Star Formation History and Evolution of the Ultra-Diffuse M81 Satellite F8D1

Abstract We present deep Hubble Space Telescope (HST) imaging of one of the nearest ultra-diffuse galaxies (UDGs) outside of the Local Group: F8D1, a satellite of M81 known to be tidally disrupting. UDGs are an enigmatic and diverse population, with evolutionary pathways ranging...

Non-ideal MHD and protostellar feedback effects on disk formation and evolution in numerical simulations of star cluster formation

Abstract While recent surveys have resolved hundreds of nearby protostellar disks, numerical simulations assuming ideal magnetohydrodynamics (MHD) have historically struggled to achieve disk formation due to efficient angular momentum removal by magnetic torques. Non-ideal MHD ef...