Los Alamos National Laboratory

Machine-learned, finite temperature Fermi-operator expansions suitable for GPUs and AI-hardware

We present several finite-temperature recursive Fermi–operator expansion schemes based on the second-order spectral projection (SP2) method. Our approach builds on a previous observation that the electronic structure problem, as formulated through a recursive SP2 expansion, can b...

A Conservative Invariant-Domain Preserving Projection Technique for Hyperbolic Systems Under Adaptive Mesh Refinement

Abstract. We propose a novel, rigorous, and conservative invariant-domain preserving (IDP) projection technique between solution spaces of differing discretizations. The projection preserves important physical invariants of the underlying hyperbolic system, for example, positivit...

Towards high-fidelity simulations of coastal submesoscale baroclinic instabilities with MPAS–O (vE3SM3.0.0) – Part 2: Realistic experiments

Abstract. River plumes can strongly influence coastal dynamics but are poorly represented in global ocean models due to stringent resolution requirements. Following the idealized simulations presented in a companion paper (Hinson et al., 2026), this study presents submesoscale-pe...

Multirate Runge–Kutta for Nonlinearly Partitioned Systems

Abstract. Multirate integration is an increasingly relevant tool that enables scientists to simulate multiphysics systems. Existing multirate methods are designed for equations whose fast and slow variables can be linearly separated using additive or componentwise partitions. How...

Quantum algorithms for general nonlinear dynamics based on the Carleman embedding

Important nonlinear dynamics, such as those found in plasma and fluid systems, are typically hard to simulate on classical computers. Thus, if fault-tolerant quantum computers could efficiently solve such nonlinear problems, it would be a transformative change for many industries...

Epigenetic insights into extreme longevity in the world’s oldest terrestrial animal, Jonathan

Aldabra giant tortoises ( Aldabrachelys gigantea ) are exceptionally long-lived. We sequenced the genome and methylome of Jonathan, a 194-year-old Aldabra, to explore the molecular basis of his longevity. Relative to other giant tortoises ( A. gigantea and Chelonoidis abingdonii...

Statistical methods for partitioning ribbon and globally-distributed flux using data from the Interstellar Boundary Explorer

NASA’s Interstellar Boundary Explorer (IBEX) satellite collects data on energetic neutral atoms (ENAs) that can provide insight into the heliosphere boundary between our solar system and interstellar space. Using these data, scientists can construct maps of the ENA intensities (o...

Experimental study of a ten sodium heat pipe bundle array with various failure modes

Alkali metal heat pipes are key components for high-temperature heat removal in microreactors, where multiple heat pipes are embedded directly within the reactor core. Their collective thermal behavior, including interactions under off-normal conditions, remains insufficiently ch...

Angular momentum drives proton-rich nucleosynthesis in hyperaccreting neutron stars in common envelopes

Abstract Interacting binaries, especially for massive star systems, produce a wide range of exotic systems including X-ray binaries and merging neutron star systems. In the rapid expansion as a star moves off the main sequence (core hydrogen exhaustion), the star can engulf its c...

High-density optical quantum sensors with pulsed probe read-out for correlated spin-noise reduction

Abstract Optical quantum sensors based on alkali-metal atoms enable highly sensitive magnetic-field measurements in warm vapor. Their performance can become limited by intrinsic spin noise once technical noise sources are sufficiently suppressed. Characterizing temporal spin corr...

Addendum: Magnetic field screening in hydrogen-rich high-temperature superconductors

In our paper 1 , we studied the magnetic response of H 3 S and LaH 10 superconductors to an applied magnetic field using Superconducting Quantum Interference Device (SQUID) magnetometry. Prof. Hirsch, in his Matters Arising entitled “On the Author Correction to “Magnetic field sc...

Beyond CD4 counts: Multi‐biomarker assessment of estimated time since HIV ‐1 infection and risk factors for late diagnosis

BACKGROUND: Late diagnosis (LD) of HIV, defined as CD4 count <350 cells/μL or AIDS at diagnosis, remains a substantial public health challenge, with half of individuals in Europe diagnosed late. How long these individuals have lived with HIV remains unclear. We applied a multi-bi...

Phosphine Coordination to Ce, Nd, Np, and Pu in Ar BiAMP t Bu ‐Supported Complexes and Their 2 H and 13 C Isotopologues

ABSTRACT 13 C‐ and 2 H‐enriched bis((3,5‐dimethylphenyl)aminomethyl) tert butylphosphine (the natural abundance (NA) ligand Ar BiAMP t Bu ; the 2 H‐ and 13 C‐labelled analogues are denoted as d 4 ‐ Ar BiAMP t Bu and 13 C 2 ‐ Ar BiAMP t Bu , respectively), containing two secondary...

Reinterpretation of ice-sheet history and geomorphology in the Lambert-Amery system, East Antarctica, from cosmogenic in-situ 14C analysis

Reconstructing the history of the Antarctic Ice Sheet provides valuable insights into ice-sheet response to climate change. The Lambert Glacier-Amery Ice Shelf system is the largest glacial system in East Antarctica, but reconstructing the state of this glacier system is challeng...

A machine learning based investigation of void distribution effects in ductile failure

The overarching goal of this work is to develop a predictive model of fracture resistance in a context of epistemic uncertainty due to analytically intractable mechanisms in metallic materials. The uncertainty associated with the spatial distribution of defects, such as voids, an...

Locking Down Science Gateways with Landlock and Seccomp

Abstract The most recent Linux kernels have a new feature for securing applications: Landlock. Like Seccomp before it, Landlock makes it possible for a running process to selectively relinquish access to certain system resources including network and filesystem access. Rather tha...

Modeling Reactions on the Solid–Liquid Interface with Next Generation Extended Lagrangian Quantum-Based Molecular Dynamics

Abstract We present a series of simulations of the oxygen reduction reaction (ORR) using a novel framework for atomistic simulations of surface catalysis under electrochemical bias. The framework makes use of quantum-mechanical extended Lagrangian Born–Oppenheimer molecular dynam...

Leveraging Mechanical Resonances for the Selection of Promising Materials in Complex Phase Spaces

ABSTRACT The “high‐entropy” paradigm has been applied to a central challenge in materials science, the design of new functional materials with enhanced performance for targeted applications, with some notable successes over the last twenty years. However, the immensity of the hig...

Modulated deuteron spectra observed with the magnetic recoil neutron spectrometer at the National Ignition Facility

The Magnetic Recoil Spectrometer (MRS) at the National Ignition Facility is used to measure the neutron spectrum from deuterium–tritium-fuelled inertial confinement fusion implosions via neutron–deuteron elastic scattering and magnetic dispersion of recoil deuterons. From the MRS...

Generative AI‐Enabled Discovery and Experimental Demonstration of Ultra‐Broadband Epsilon‐Near‐Zero Perfect Absorbers

ABSTRACT Artificial intelligence is reshaping the discovery and engineering of photonic materials. Here, we introduce a data‐driven framework that employs a generative deep neural network to create ultrathin, multilayer epsilon‐near‐zero absorbers with record‐breaking broadband p...