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DOE OSTI2020

The Mini Astrophysical MeV Background Observatory (MAMBO) CubeSat mission

The origin of the cosmic diffuse gamma-ray (CDG) background in the 0.3 – 30 MeV energy range is a mystery that has persisted for over 40 years. The Mini Astrophysical MeV Background Observatory (MAMBO) is a CubeSat mission concept motivated by the fact that, since the MeV CDG is relatively bright, only a small detector is required to make highquality measurements of it. Indeed, the sensitivity of space-based gamma-ray instruments to the CDG is limited not by size, but by the locally generated instrumental background produced by interactions of energetic particles in spacecraft materials. Comparatively tiny CubeSat platforms provide a uniquely quiet environment relative to previous gamma-ray science missions. The MAMBO mission will provide the best measurements ever made of the MeV CDG spectrum and angular distribution, utilizing two key innovations: 1) low instrumental background on a 12U CubeSat platform; and 2) an innovative shielded spectrometer design that simultaneously measures signal and background. We describe the MAMBO instrument and mission concept in detail, including simulations and laboratory measurements demonstrating the key measurement concept.

Astronomy and astrophysics↗

DOE OSTI2021

Gradient cell–structured high-entropy alloy with exceptional strength and ductility

We report that similar to conventional materials, most multicomponent high-entropy alloys (HEAs) lose ductility as they gain strength. In this study, we controllably introduced gradient nanoscaled dislocation cell structures in a stable single-phase HEA with face-centered cubic structure, thus resulting in enhanced strength without apparent loss of ductility. Upon application of strain, the sample-level structural gradient induces progressive formation of a high density of tiny stacking faults (SFs) and twins, nucleating from abundant low-angle dislocation cells. Furthermore, the SF-induced plasticity and the resultant refined structures, coupled with intensively accumulated dislocations, contribute to plasticity, increased strength, and work hardening. These findings offer a promising paradigm for tailoring properties with gradient dislocation cells at the nanoscale and advance our fundamental understanding of the intrinsic deformation behavior of HEAs.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Atomic faulting induced exceptional cryogenic strain hardening in gradient cell–structured alloy

Coarse-grained materials are widely accepted to display the highest strain hardening and the best tensile ductility. We experimentally report an attractive strain hardening rate throughout the deformation stage at 77 kelvin in a stable single-phase alloy with gradient dislocation cells that even surpasses its coarse-grained counterparts. Contrary to conventional understanding, the exceptional strain hardening arises from a distinctive dynamic structural refinement mechanism facilitated by the emission and motion of massive multiorientational tiny stacking faults (planar defects), which are fundamentally distinct from the traditional linear dislocation–mediated deformation. In conclusion, the dominance of atomic-scale planar deformation faulting in plastic deformation introduces a different approach for strengthening and hardening metallic materials, offering promising properties and potential applications.

Gradient dislocation structure↗

DOE OSTI2021

A Simple, Cost-Effective, and Automation-Friendly Direct PCR Approach for Bacterial Community Analysis

Understanding bacterial interactions and assembly in complex microbial communities using 16S rRNA sequencing normally requires a large experimental load. However, the current DNA extraction methods, including cell disruption and genomic DNA purification, are normally biased, costly, time-consuming, labor-intensive, and not amenable to miniaturization by droplets or 1,536-well plates due to the significant DNA loss during the purification step for tiny-volume and low-cell-density samples.

16S rRNA sequencing↗

DOE OSTI2022

Measuring the electron Yukawa coupling via resonant s-channel Higgs production at FCC-ee

The Future Circular Collider (FCC-ee) offers the unique opportunity of studying the Higgs Yukawa coupling to the electron, \(y_\mathrm {e}\) , via resonant s -channel production, \(\mathrm {e^+e^-}\rightarrow \mathrm {H}\) , in a dedicated run at \(\sqrt{s} = m_\mathrm {H}\) . The signature for direct Higgs production is a small rise in the cross sections for particular final states, consistent with Higgs decays, over the expectations for their occurrence due to Standard Model (SM) background processes involving \(\mathrm {Z}^*\) , \(\gamma ^*\) , or t -channel exchanges alone. Performing such a measurement is remarkably challenging for four main reasons. First, the low value of the e \(^\pm \) mass leads to a tiny \(y_\mathrm {e}\) coupling and correspondingly small cross section: \(\sigma _\mathrm {ee\rightarrow H} \propto m_\mathrm {e}^2 = 0.57\) fb accounting for initial-state \(\gamma \) radiation. Second, the \(\mathrm {e^+e^-}\) beams must be monochromatized such that the spread of their centre-of-mass (c.m.) energy is commensurate with the narrow width of the SM Higgs boson, \(\varGamma _\mathrm {H} = 4.1\) MeV, while keeping large beam luminosities. Third, the Higgs mass must also be known beforehand with a few-MeV accuracy in order to operate the collider at the resonance peak, \(\sqrt{s} = m_\mathrm {H}\) . Last but not least, the cross sections of the background processes are many orders-of-magnitude larger than those of the Higgs decay signals. A preliminary generator-level study of 11 Higgs decay channels using a multivariate analysis, which exploits boosted decision trees to discriminate signal and background events, identifies two final states as the most promising ones in terms of statistical significance: \(\mathrm {H}\rightarrow gg\) and \(\mathrm {H}\rightarrow \mathrm {W}\mathrm {W}^*\!\rightarrow \ell \nu \) + 2 jets. For a benchmark monochromatization with 4.1-MeV c.m. energy spread (leading to \(\sigma _\mathrm {ee\rightarrow H} = 0.28\) fb) and 10 ab \(^{-1}\) of integrated luminosity, a \(1.3\sigma \) signal significance can be reached, corresponding to an upper limit on the e \(^\pm \) Yukawa coupling at 1.6 times the SM value: |y e | < 1.6|y e SM | at 95% confidence level, per FCC-ee interaction point per year. Directions for future improvements of the study are outlined.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2023

Bremsstrahlung from neutrino scattering via magnetic dipole moments

In this paper, we discuss bremsstrahlung induced by neutrino scattering. This process should exist since neutrinos are expected to couple to photons via magnetic dipole and transition moments. These moments are loop-induced and tiny in the Standard Model with neutrino masses but could be significantly enhanced in extended theories. As concrete example, we study the scattering of the two largest neutrino fluxes on earth, solar neutrinos and Cosmic Neutrino Background (CNB). Finally, it is tempting to consider this as a potential signature for CNB searches but it turns out that the signal is extremely small and unlikely to be observed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2023

Emergent Halperin–Saslow mode, gauge glass and quenched disorders in quantum Ising magnet TmMgGaO 4

Quenched disorders could bring novel quantum excitations and models to certain quantum magnets. Motivated by recent experiments on the quantum Ising magnet TmMgGaO 4 , we explore the effects of the quenched disorder and the interlayer coupling in this triangular lattice Ising antiferromagnet. It is pointed out that the weak quenched (nonmagnetic) disorder would convert the emergent 2D Berezinskii–Kosterlitz–Thouless (BKT) phase and the critical region into a U(1) gauge glass. There will be an emergent Halperin–Saslow mode associated with this gauge glass. Using the Imry-Ma’s renormalization group result, we explain the fate of the finite-field [Formula: see text] symmetry breaking transition at the low temperatures. The ferromagnetic interlayer coupling would suppress the BKT phase and generate a tiny ferromagnetism. With quenched disorders, this interlayer coupling changes the 2D gauge glass into a 3D gauge glass, and the Halperin–Saslow mode persists. This work merely focuses on addressing a phase regime in terms of emergent U(1) gauge glass behaviors and hope to inspire future works and thoughts in weakly disordered frustrated magnets in general.

Physics↗

DOE OSTI2025

TorchBraid: High-Performance Layer-Parallel Training of Deep Neural Networks with MPI and GPU Acceleration

TorchBraid is a high-performance implementation of layer-parallel training for deep neural networks (DNNs) supporting MPI-based parallelism and GPU acceleration. Layer-parallel training has been developed to overcome the serialization inherent in forward and backward propagation of DNNs that limits utilization of computational resources in the strong scaling limit. To achieve this, TorchBraid integrates the PyTorch neural network framework with the state-of-the-art XBraid time-parallel library. Furthermore, this article presents the use and performance of TorchBraid, in addition to solutions for overcoming the algorithmic challenges inherent in combining automatic differentiation with layer-parallel. Results are presented with and without GPU acceleration for the Tiny ImageNet and MNIST image classification data sets, as well as recurrent neural networks. Overall, TorchBraid enables fast training of DNNs, both in a strong and weak scaling context. In addition to the TorchBraid software, several new advances in applying layer-parallel algorithms are detailed. Integration of layer-parallel with data-parallel algorithms is presented for the first time, showing the computational advantages of the combination. Standard deep learning techniques, like batch-normalization, are developed for layer-parallel training. Finally, a new approach combining layer-parallel with spatial coarsening in order to accelerate training for 3D image classification shows roughly a 10× speedup over serial execution.

Layer-parallel↗

DOE OSTI2025

Self-Supervised T-GCN for Detection of Disturbance and Propagation in Power Grid

Urban power systems increasingly rely on dense sensing to monitor grid reliability, yet disturbance labels are scarce and events are rare. We present a self-supervised spatio-temporal method that detects, localizes, and characterizes grid frequency disturbances across urban areas using only unlabeled data. Our approach trains a tiny Temporal Graph Convolutional Network (T-GCN) to forecast per-site frequency residuals (deviation from 60 Hz). The sensor graph is constructed directly from signals using pre-event Pearson correlation with a cross-correlation lag penalty without geocoding. At inference, node-level anomalies are the model's forecast errors; region-level alarms arise from connected components of high-score nodes. We estimate disturbance propagation by computing per-node arrival times (first persistent exceedance), then fit a planar or time-of-arrival model to obtain direction, speed, and an epicenter proxy. With only three real events collected at decisecond resolution across U.S. cities, we evaluate the T-GCN and report time-to-detect, footprint size, and propagation consistency. We further show that short-window embeddings from the T-GCN's hidden states enable few-shot event-vs-background recognition via a simple prototypical classifier. Despite minimal data and no labels, our system yields fast, spatially coherent detection and interpretable propagation maps, offering a practical, lightweight pathway to city-scale grid resilience analytics.

Niu, Haoran [ORNL] (ORCID:0000000155228297)↗

DOE OSTI2021

Characterization of Nanoscale Pores in Tight Gas Sandstones Using Complex Techniques: A Case Study of a Linxing Tight Gas Sandstone Reservoir

Pore structures with rich nanopores and permeability in tight gas reservoirs are poorly understood up to date. Advanced techniques are needed to be employed to accurately characterize pore structures, especially tiny pores which include micron and nanopores. In this study, various experimental techniques such as scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) T 2 , nitrogen adsorption method, and NMR cryoporometry (NMRC) are combined to interrogate the complex pore systems of the tight gas reservoir in the Linxing formation, Ordos Basin, China. Results show that tight gas sandstones are primarily comprised of residual interparticle and clay-dominated pores. Clay and quartz are two dominate minerals while pyrite occupies a nontrivial amount as well. The permeability of tight gas sandstones is very low, exhibiting an extremely poor positive correlation with porosity. While pore types and relative pore contents are more influential factors on the permeability, accurate characterization of pore size distribution is critical for the permeability of tight gas sandstones. Therefore, complementary characterization methods are carried out, indicating that neither small pores with radii < 100 nm (around peak 1 in NMR T 2 distribution) nor large pores with radii > 5 μ m (around peak 3 in NMR T 2 distribution) control the permeability by analyzing the connectivity of the pores in various size ranges, but rather pores averaging approximately 350 ± X nm (around peak 2 in NMR T 2 distribution) have sufficient connectivity to host and transmit hydrocarbons. The pore size of tight gas sandstones is dominated by the clay-rich mineral assemblage. The study shows that the NMRC technique can be a very promising method, especially when referred to as a promising “roadmap” on how to interrogate tight formations such as the tight gas sands or even shale especially for the nanopore characterization.

15 GEOTHERMAL ENERGY↗

DOE OSTI2021

Light transport with weak angular dependence in fog

Random scattering and absorption of light by tiny particles in aerosols, like fog, reduce situational awareness and cause unacceptable down-time for critical systems or operations. Computationally efficient light transport models are desired for computational imaging to improve remote sensing capabilities in degraded optical environments. To this end, we have developed a model based on a weak angular dependence approximation to the Boltzmann or radiative transfer equation that appears to be applicable in both the moderate and highly scattering regimes, thereby covering the applicability domain of both the small angle and diffusion approximations. An analytic solution was derived and validated using experimental data acquired at the Sandia National Laboratory Fog Chamber facility. The evolution of the fog particle density and size distribution were measured and used to determine macroscopic absorption and scattering properties using Mie theory. A three-band (0.532, 1.55, and 9.68 µ m) transmissometer with lock-in amplifiers enabled changes in fog density of over an order of magnitude to be measured due to the increased transmission at higher wavelengths, covering both the moderate and highly scattering regimes. The meteorological optical range parameter is shown to be about 0.6 times the transport mean free path length, suggesting an improved physical interpretation of this parameter.

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2024

Shrub Heights at the Teller 27 and Kougarok 64 Field Sites, Seward Peninsula, Alaska, 2021

As shrubs become more widespread across the Arctic, there is increasing focus on their influence over snow accumulation and soil moisture. To better characterize shrub heights based on landscape position, proximity to surface waters, and species, shrub heights were measured with a differential GPS (dGPS) at the Teller 27 and Kougarok 64 field sites on the Seward Peninsula, Alaska. Measurements were collected between September 12th through 16th, 2021. Shrub heights were calculated by subtracting the maximum height of the canopy from the ground elevation. Some of the shrub heights collected were co-located with iButton (i.e., K45, B8) and Tiny Tag (i.e., TT10) sensors in dataset NGA296. Other shrub heights and species were measured in a dense 20 m x 20 m plot to understand shrub density, species composition, and heights. This dataset contains a .csv file of ground elevations and shrub heights of shrubs throughout the Teller 27 and Kougarok 64 sites.The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy’s Office of Biological and Environmental Research.The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska.Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy’s Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

Materials Data on Ti2CoNi by Materials Project

TiNi(TiCo) crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. there are six inequivalent Ti sites. In the first Ti site, Ti is bonded in a 2-coordinate geometry to four equivalent Ti, four Co, and two equivalent Ni atoms. All Ti–Ti bond lengths are 2.84 Å. There are two shorter (2.70 Å) and two longer (2.71 Å) Ti–Co bond lengths. Both Ti–Ni bond lengths are 2.56 Å. In the second Ti site, Ti is bonded in a 2-coordinate geometry to four equivalent Ti, two equivalent Co, and four Ni atoms. All Ti–Ti bond lengths are 2.86 Å. Both Ti–Co bond lengths are 2.73 Å. There are two shorter (2.55 Å) and two longer (2.68 Å) Ti–Ni bond lengths. In the third Ti site, Ti is bonded in a 2-coordinate geometry to two equivalent Ti, three Co, and three Ni atoms. There are one shorter (2.83 Å) and one longer (2.85 Å) Ti–Ti bond lengths. There are a spread of Ti–Co bond distances ranging from 2.69–2.73 Å. There are a spread of Ti–Ni bond distances ranging from 2.55–2.70 Å. In the fourth Ti site, Ti is bonded in a 2-coordinate geometry to four equivalent Ti, two equivalent Co, and four Ni atoms. All Ti–Ti bond lengths are 3.05 Å. Both Ti–Co bond lengths are 2.75 Å. There are two shorter (2.57 Å) and two longer (2.71 Å) Ti–Ni bond lengths. In the fifth Ti site, Ti is bonded in a 2-coordinate geometry to four equivalent Ti, four Co, and two equivalent Ni atoms. All Ti–Ti bond lengths are 3.02 Å. There are two shorter (2.55 Å) and two longer (2.73 Å) Ti–Co bond lengths. Both Ti–Ni bond lengths are 2.72 Å. In the sixth Ti site, Ti is bonded in a 2-coordinate geometry to eight Ti, three Co, and three Ni atoms. There are one shorter (3.01 Å) and one longer (3.06 Å) Ti–Ti bond lengths. There are a spread of Ti–Co bond distances ranging from 2.53–2.76 Å. There are one shorter (2.59 Å) and two longer (2.72 Å) Ti–Ni bond lengths. There are three inequivalent Co sites. In the first Co site, Co is bonded to six Ti, one Co, and five Ni atoms to form face-sharing CoTi6CoNi5 cuboctahedra. The Co–Co bond length is 2.37 Å. There are two shorter (2.37 Å) and three longer (2.39 Å) Co–Ni bond lengths. In the second Co site, Co is bonded to six Ti, two equivalent Co, and four Ni atoms to form face-sharing CoTi6Co2Ni4 cuboctahedra. Both Co–Co bond lengths are 2.38 Å. There are two shorter (2.38 Å) and two longer (2.39 Å) Co–Ni bond lengths. In the third Co site, Co is bonded in a 12-coordinate geometry to six Ti, four Co, and two equivalent Ni atoms. The Co–Co bond length is 2.67 Å. Both Co–Ni bond lengths are 2.65 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to six Ti, five Co, and one Ni atom. The Ni–Ni bond length is 2.63 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to six Ti, three Co, and two equivalent Ni atoms. Both Ni–Ni bond lengths are 2.67 Å. In the third Ni site, Ni is bonded in a 12-coordinate geometry to six Ti, three Co, and three Ni atoms. The Ni–Ni bond length is 2.65 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ti2CoNi by Materials Project

TiNi(TiCo) is Heusler-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ti is bonded in a body-centered cubic geometry to four equivalent Co and four equivalent Ni atoms. All Ti–Co bond lengths are 2.58 Å. All Ti–Ni bond lengths are 2.60 Å. Co is bonded in a body-centered cubic geometry to eight equivalent Ti atoms. Ni is bonded in a body-centered cubic geometry to eight equivalent Ti atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2023

AmeriFlux FLUXNET-1F US-xDC NEON Dakota Coteau Field School (DCFS)

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-xDC NEON Dakota Coteau Field School (DCFS). This is the FLUXNET version of the carbon flux data for the site US-xDC NEON Dakota Coteau Field School (DCFS) produced by applying the standard ONEFlux (1F) software. Site Description - The Dakota Coteau Field School (DCFS) and Prairie Lake (PRLA) field sites are co-located in an agricultural area used primarily for cattle grazing, just a few miles east of the Woodworth and Prairie Pothole sites at the Chase Lake National Wildlife Refuge. DCFS covers 7.8 km2 (3 square miles) of grazing land in Stutsman County, ND, between the tiny communities of Pingree and Woodworth. The population here is sparse, but the land has been transformed by agricultural activities over the last 150 years. The field site has been used only for grazing, but other land in the surrounding area has been converted to corn and soybean production. DCFS is located in an area known as the "Prairie Pothole Region," a band of tall and mixed prairie that stretches across parts of North and South Dakota, Minnesota and the Canadian provinces of Alberta, Saskatchewan and Manitoba. Historically, this area supported tall to mid-height prairie grasses, including blue gamma and green needlegrass. The land here is pocked by thousands of depressions left behind by glaciers 10,000 years ago, resulting in a series of small lakes and wetland areas known as prairie potholes. These potholes receive most of their water from spring snowmelt and are a primary source of groundwater recharge for the region. NEON data will help researchers monitor the effects of climate change on the Northern Plains ecosystem. Over the last 30 years, the hydrological cycle in the plains has changed dramatically, trending wetter overall and diverging from the historical ten-year cycles. Temperatures are also rising, leading to changes in plant phenology cycles and species distribution that could negatively impact migratory bird populations and other animal species.

Network), NEON (National Ecological Observatory↗

DOE OSTI2020

Next Generation Noble Liquid Detectors

The research program here combines Generic and Directed R\&D for Liquid Noble Gas detectors for neutrino physics and dark matter. In neutrino physics and dark matter research, we are addressing some of the most fundamental questions in particle physics today by studying these tiny particles in the electron family. To study them, detectors must be large, high precision, and ideally have the ability to collect detailed information from both charge and light from neutrino and dark matter interactions. Precision detection combined with large scales can be challenging. Liquid Argon detectors mitigate some of these challenges given the nature of its interaction medium and it’s relatively inexpensive cost per ton. Significant progress has been made in the last 15 years in developing these kinds of detectors to be built and operated at large scales. However there are still challenges and new ideas in moving these detectors from ton scale to kiloton scale. To be able to get the most out of these kinds of detectors directed questions with respect to specific components running and colleting data in the detectors must be understood. As well, new ideas on how to best combine charge and light measurements may lead to new ways to learn new things with these detectors. Experimental test stands to conduct this work, as is done in this proposal, to accomplish both of these goals are critical to address both of these questions. In the test stand enabled under this grant at Yale University’s Wright lab, new developments in efficient small scale setups were developed, instrumentation developed for running and future experiments (the SBND experiment at Fermilab at present, the DUNE experiment in the future) were and will be tested, and new ideas for charge and light determination for new measurements are under study. The long term impact of this work in neutrino physcis is both for the short and long baseline programs originating at Fermi National Accelerator Laboratory. At long baselines, the US flagship DUNE experiment will measure neutrino properties through neutrino oscillations using a beam originating at Fermilab and a massive LArTPC detector sited about a mile underground at the Sanford Underground Research Facility in Lead, South Dakota. Studies here on the high voltage for thes detectors, and ongoing work on charge and light production and collection in the TPC are relevant for the design and data taking of this and other LArTPC detectors to enable them to best measure the neutrinos created at Fermilab that then pass through the detector in South Dakota. What we learn in these detectors may ultimately change the course of how we understand neutrino’s impact in the early universe. What we learn about how to improve this detection technology and develop new ideas in Lar detectors in general may impact both future neutrino experiments and dark matter experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2020

A look back 75 years at Little Boy, the crew, the plane and the Lab’s first mission

Hours before the sun would rise over Tinian island on the morning of August 6, 1945, a B- 29 airplane was positioned above a specially built bomb-loading pit, as crews readied it with cargo unlike anything the world had ever known. Preparations on the tiny Pacific island—nearly 6,600 miles from Los Alamos and about 1,500 miles from its intended target in Japan—had begun months before on April 3. And months before that, pilot Paul Tibbets Jr. and his crew had practiced dropping dummy concrete bombs on targets in Utah. Even years before that, development of this cargo destined for Japan began in secrecy under the direction of a physicist and an Army general in the mountains of Northern New Mexico. It was all leading to one day that would help end years of bloodshed and change the world forever.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

DOE OSTI2020

Confronting Dark Matter with the Multiwavelength Sky (Final Technical Report)

The existence of dark matter is a key clue to new fundamental physics, yet its nature and non-gravitational interactions remain mysterious. In the course of this five-year project (spanning July 2015 - July 2020), we have developed novel analysis techniques to separate dark matter signals from astrophysical backgrounds in the inner Galaxy, and measured hitherto-unknown properties of the Fermi Bubbles and the Galactic Center excess in gamma-rays from the inner Milky Way. We have improved predictions for the spatial distribution and energy spectra of photon signals from dark matter, and set new limits from astrophysical and cosmological datasets on dark matter inhabiting complex dark sectors, multi-particle dark matter annihilation, and tiny primordial black holes. We have successfully adapted effective field theory techniques from collider physics to make high-precision predictions for signals from heavy weakly-interacting DM, allowing us to essentially exclude the possibility that DM is a thermal wino, and have discovered novel theoretical and observational implications for dark matter bound states and self-interactions. We have developed a comprehensive public code package for modeling the effects of exotic energy injections, such as from dark matter annihilation and decay, on the ionization and temperature history of the early cosmos, and have used these tools to set robust, powerful and broadly-applicable constraints on models of light dark matter.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗