About

Professor William J. Evans is a faculty member at the Eddleman Quantum Institute at the University of California, Irvine. His research focuses on the synthesis of rare-earth metal compounds, single-molecule magnets, and molecular qubits. As the director of the institute, he contributes to advancing quantum science through interdisciplinary collaboration and education. His work is integral to the institute's concentrated effort on rare-earth metals, which are valuable in exploring the frontiers of quantum science and developing new quantum phenomena.

Research topics

• Physics
• Astrophysics
• Astronomy
• Optics
• Particle physics
• Nuclear physics

Selected publications

• City of Irvine Climate Sustainability Commission: Crisis Action Report

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-22

  reportOpen access1st authorCorresponding

  Executive Summary I submit this report to the Mayor, the City Council, and my colleagues on the Sustainability Commission on the occasion of Earth Day 2026. It is an update to the report I wrote in April 2021 for the Green Ribbon Environmental Committee (GREC) on the physical and financial potential of a solar-powered Irvine, revised and broadened five years later with the benefit of the City’s 2019 Greenhouse Gas Inventory, the September 2025 Public Draft of the Climate Action and Adaptation Plan (CAAP), and the continuing advance of the technologies, financing tools, and state programs that make my original conclusions even more achievable today than they were then. I write in the conviction that the City of Irvine, as a community, as a government, and as a civic tradition, has both the obligation and the capacity to act decisively on the climate crisis. Our own emissions are accelerating the crisis. Deferring responsibility to the county, state, federal, or international levels is, in my view, no longer a defensible posture for a city of Irvine’s sophistication, means, and ethical leadership. Taking the 2021 ACHIEVES Resolution (Resolution No. 21-50) as my foundation, and drawing on the 2019 GHG Inventory and the draft CAAP, I identify three actions the City can take now that, together, would retire the overwhelming majority of Irvine’s community-wide greenhouse gas (GHG) emissions: 1. Immediately halt new natural gas infrastructure installation and begin an orderly transition of existing gas loads to electric alternatives. 2. Scale the One Irvine program into a universal, city-financed Solarize-and-Electrify revolving loan, delivering rooftop solar, battery storage, heat-pump water heating and space conditioning, and electric vehicle (EV) charging to every willing household at zero upfront cost, repayable at property transfer. This is a direct generalization of the revolving-fund concept I proposed in my 2021 report. 3. Accelerate transportation electrification through municipal financing for resident EV purchases, aggressive deployment of DC fast charging at city parks and multi-family sites, and an honest, electric-bus-forward redesign of the Irvine CONNECT shuttle so that it becomes a net carbon reducer rather than, as I show in Section 2.3, a net carbon emitter. I include an appendix documenting how recent decisions by the California Public Utilities Commission (CPUC), specifically the retroactive revision of the Power Charge Indifference Adjustment (PCIA) methodology under Decision 25-06-049, have shifted costs away from investor-owned utility (IOU) customers and onto Community Choice Energy (CCE) customers. This regulatory capture is, in my judgment, the primary driver of the current, temporary increase in OCPA rates and is the single greatest external threat to the City’s decarbonization pathway. The City of Irvine, Orange County, and our state delegation must push back as one. Section 3 of this report addresses a question that arises naturally in any discussion of climate strategy: whether the City can offset its emissions by planting more trees. The Urban Forest Master Plan (UFMP) is a valuable program, but the arithmetic of tree sequestration is unambiguous. Offsetting Irvine’s community-wide emissions through tree planting alone would require on the order of 75 million new trees every year, against a UFMP planting target of 1,900 per year. Trees are a meaningful co-benefit; they are not a climate lever at the scale the ACHIEVES Resolution requires. None of this is easy. All of it is possible. The question before us is not whether Irvine can lead, but whether Irvine will.

  PublisherDOI

• City of Irvine Sustainability Commission: Climate Crisis Action Report

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-22

  reportOpen access1st authorCorresponding

  Executive Summary I submit this report to the Mayor, the City Council, and my colleagues on the Sustainability Commission on the occasion of Earth Day 2026. It is an update to the report I wrote in April 2021 for the Green Ribbon Environmental Committee (GREC) on the physical and financial potential of a solar-powered Irvine, revised and broadened five years later with the benefit of the City’s 2019 Greenhouse Gas Inventory, the September 2025 Public Draft of the Climate Action and Adaptation Plan (CAAP), and the continuing advance of the technologies, financing tools, and state programs that make my original conclusions even more achievable today than they were then. I write in the conviction that the City of Irvine, as a community, as a government, and as a civic tradition, has both the obligation and the capacity to act decisively on the climate crisis. Our own emissions are accelerating the crisis. Deferring responsibility to the county, state, federal, or international levels is, in my view, no longer a defensible posture for a city of Irvine’s sophistication, means, and ethical leadership. Taking the 2021 ACHIEVES Resolution (Resolution No. 21-50) as my foundation, and drawing on the 2019 GHG Inventory and the draft CAAP, I identify three actions the City can take now that, together, would retire the overwhelming majority of Irvine’s community-wide greenhouse gas (GHG) emissions: 1. Immediately halt new natural gas infrastructure installation and begin an orderly transition of existing gas loads to electric alternatives. 2. Scale the One Irvine program into a universal, city-financed Solarize-and-Electrify revolving loan, delivering rooftop solar, battery storage, heat-pump water heating and space conditioning, and electric vehicle (EV) charging to every willing household at zero upfront cost, repayable at property transfer. This is a direct generalization of the revolving-fund concept I proposed in my 2021 report. 3. Accelerate transportation electrification through municipal financing for resident EV purchases, aggressive deployment of DC fast charging at city parks and multi-family sites, and an honest, electric-bus-forward redesign of the Irvine CONNECT shuttle so that it becomes a net carbon reducer rather than, as I show in Section 2.3, a net carbon emitter. I include an appendix documenting how recent decisions by the California Public Utilities Commission (CPUC), specifically the retroactive revision of the Power Charge Indifference Adjustment (PCIA) methodology under Decision 25-06-049, have shifted costs away from investor-owned utility (IOU) customers and onto Community Choice Energy (CCE) customers. This regulatory capture is, in my judgment, the primary driver of the current, temporary increase in OCPA rates and is the single greatest external threat to the City’s decarbonization pathway. The City of Irvine, Orange County, and our state delegation must push back as one. Section 3 of this report addresses a question that arises naturally in any discussion of climate strategy: whether the City can offset its emissions by planting more trees. The Urban Forest Master Plan (UFMP) is a valuable program, but the arithmetic of tree sequestration is unambiguous. Offsetting Irvine’s community-wide emissions through tree planting alone would require on the order of 75 million new trees every year, against a UFMP planting target of 1,900 per year. Trees are a meaningful co-benefit; they are not a climate lever at the scale the ACHIEVES Resolution requires. None of this is easy. All of it is possible. The question before us is not whether Irvine can lead, but whether Irvine will.

  PublisherDOI

• City of Irvine Sustainability Commission: Climate Crisis Action Report

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-22

  reportOpen access1st authorCorresponding

  Executive Summary I submit this report to the Mayor, the City Council, and my colleagues on the Sustainability Commission on the occasion of Earth Day 2026. It is an update to the report I wrote in April 2021 for the Green Ribbon Environmental Committee (GREC) on the physical and financial potential of a solar-powered Irvine, revised and broadened five years later with the benefit of the City’s 2019 Greenhouse Gas Inventory, the September 2025 Public Draft of the Climate Action and Adaptation Plan (CAAP), and the continuing advance of the technologies, financing tools, and state programs that make my original conclusions even more achievable today than they were then. I write in the conviction that the City of Irvine, as a community, as a government, and as a civic tradition, has both the obligation and the capacity to act decisively on the climate crisis. Our own emissions are accelerating the crisis. Deferring responsibility to the county, state, federal, or international levels is, in my view, no longer a defensible posture for a city of Irvine’s sophistication, means, and ethical leadership. Taking the 2021 ACHIEVES Resolution (Resolution No. 21-50) as my foundation, and drawing on the 2019 GHG Inventory and the draft CAAP, I identify three actions the City can take now that, together, would retire the overwhelming majority of Irvine’s community-wide greenhouse gas (GHG) emissions: 1. Immediately halt new natural gas infrastructure installation and begin an orderly transition of existing gas loads to electric alternatives. 2. Scale the One Irvine program into a universal, city-financed Solarize-and-Electrify revolving loan, delivering rooftop solar, battery storage, heat-pump water heating and space conditioning, and electric vehicle (EV) charging to every willing household at zero upfront cost, repayable at property transfer. This is a direct generalization of the revolving-fund concept I proposed in my 2021 report. 3. Accelerate transportation electrification through municipal financing for resident EV purchases, aggressive deployment of DC fast charging at city parks and multi-family sites, and an honest, electric-bus-forward redesign of the Irvine CONNECT shuttle so that it becomes a net carbon reducer rather than, as I show in Section 2.3, a net carbon emitter. I include an appendix documenting how recent decisions by the California Public Utilities Commission (CPUC), specifically the retroactive revision of the Power Charge Indifference Adjustment (PCIA) methodology under Decision 25-06-049, have shifted costs away from investor-owned utility (IOU) customers and onto Community Choice Energy (CCE) customers. This regulatory capture is, in my judgment, the primary driver of the current, temporary increase in OCPA rates and is the single greatest external threat to the City’s decarbonization pathway. The City of Irvine, Orange County, and our state delegation must push back as one. Section 3 of this report addresses a question that arises naturally in any discussion of climate strategy: whether the City can offset its emissions by planting more trees. The Urban Forest Master Plan (UFMP) is a valuable program, but the arithmetic of tree sequestration is unambiguous. Offsetting Irvine’s community-wide emissions through tree planting alone would require on the order of 75 million new trees every year, against a UFMP planting target of 1,900 per year. Trees are a meaningful co-benefit; they are not a climate lever at the scale the ACHIEVES Resolution requires. None of this is easy. All of it is possible. The question before us is not whether Irvine can lead, but whether Irvine will.

  PublisherDOI

• Cosmic Structure Strikes Back: The Elimination of Vector-Mediated Nonstandard Interaction Models as a Mechanism for Sterile Neutrino Dark Matter Production

  arXiv (Cornell University) · 2025-09-06

  preprintOpen accessSenior author

  We revisit sterile-neutrino production enabled by nonstandard interactions (NSI) among active neutrinos mediated by new bosons. We focus on vector mediators, including neutrinophilic, gauged $L_μ\!-\!L_τ$, and $B\!-\!L$ realizations that modify in-medium dispersion and scattering, thereby altering the active-sterile conversion history. Building on a novel production framework with NSI thermal potentials and collision integrals, we compute nonthermal phase-space distributions across sterile neutrino mixing and NSI parameters and map each point to an equivalent thermal warm dark matter particle mass $m_\mathrm{th}$ via linear-theory transfer function fitting with cosmological structure-formation Boltzmann solver. This enables a direct reinterpretation of state-of-the-art structure-formation limits from Milky Way satellites, strong lensing, and the Lyman-$α$ forest. These limits, in conjunction with X-ray decay searches, as well as results from a wide variety of particle physics experiments allow for a more complete examination of these models. We find that these vector-mediated models are ruled out when the full combination of current constraints, listed above, are taken into account. NSI scalar-mediated models and models with low-reheating temperatures remain viable.

  PublisherOA PDFDOI

• JWST Lensed Quasar Dark Matter Survey III: Dark Matter Sensitive Flux Ratios and Warm Dark Matter Constraint from the Full Sample

  ArXiv.org · 2025-11-11

  preprintOpen access

  We present the full sample of measurements of the warm dust emission of 31 strongly-lensed, multiply imaged quasars, observed with JWST MIRI multiband imaging, which we use to constrain the particle properties of dark matter. The strongly lensed warm dust region of quasars is compact and statistically sensitive to a population of dark matter halos down to masses of $10^6$ M$_\odot$. The high spatial resolution and infrared sensitivity of MIRI make it uniquely suited to measure multiply imaged warm dust emission from quasars and thus to infer the properties of low-mass dark halos. We use the measured flux ratios to test for a warm dark matter turnover in the halo mass function. To infer the dark matter parameters, we use a forward modeling pipeline which explores dark matter parameters while also accounting for tidal stripping effects on subhalos, globular clusters, and complex deflector macromodels with $m=1, m=3, \text{ and } m=4$ elliptical multipole moments. Adopting a comparable prior on the projected density of substructure to our previous analyses, the data presented here provide a factor of 2 improvement in sensitivity to a turnover in the halo mass function. Assuming subhalo abundance predicted by the semi-analytic model galacticus we infer with a Bayes factor of 10:1, a half-mode mass $m_{\rm{hm}} < 10^{7.8} M_{\odot}$ (m>5.6 keV for a thermally produced dark matter particle). If instead we use a prior from N-body simulations, we infer $m_{\rm{hm}} < 10^{7.6} M_{\odot}$ (m>6.4 keV). This is one of the strongest constraints to date on a turnover on the halo mass function, and the flux ratios and inference methodology presented here can be used to test a broad range of dark matter physics.

  PublisherOA PDFDOI

• JWST lensed quasar dark matter survey IV: Stringent warm dark matter constraints from the joint reconstruction of extended lensed arcs and quasar flux ratios

  ArXiv.org · 2025-11-10

  preprintOpen access

  We present a measurement of the free-streaming length of dark matter (DM) and subhalo abundance around 28 quadruple image strong lenses using observations from JWST MIRI presented in Paper III of this series. We improve on previous inferences on DM properties from lensed quasars by simultaneously reconstructing extended lensed arcs with image positions and relative magnifications (flux ratios). Our forward modeling framework generates full populations of subhalos, line-of-sight halos, and globular clusters, uses an accurate model for subhalo tidal evolution, and accounts for free-streaming effects on halo abundance and concentration. Modeling lensed arcs leads to more-precise model-predicted flux ratios, breaking covariance between subhalo abundance and the free-streaming scale parameterized by the half-mode mass $m_{\rm{hm}}$. Assuming subhalo abundance predicted by the semi-analytic model {\tt{galacticus}} ($N$-body simulations), we infer (Bayes factor of 10:1) $m_{\rm{hm}} < 10^{7.4} \mathrm{M}_{\odot}$ ($m_{\rm{hm}} < 10^{7.2} \mathrm{M}_{\odot}$), a 0.4 dex improvement relative to omitting lensed arcs. These bounds correspond to lower limits on thermal relic DM particle masses of $7.4$ and $8.4$ keV, respectively. Conversely, assuming DM is cold, we infer a projected mass in subhalos ($10^6 < m/M_{\odot}<10^{10.7}$) of $1.7_{-1.2}^{+2.6} \times 10^7 \ \mathrm{M}_{\odot} \ \rm{kpc^{-2}}$ at $95 \%$ confidence. This is consistent with {\tt{galacticus}} predictions ($0.9 \times 10^7 \mathrm{M}_{\odot} \ \rm{kpc^{-2}}$), but in mild tension with recent $N$-body simulations ($0.6 \times 10^7 \mathrm{M}_{\odot} \ \rm{kpc^{-2}}$). Our results are among the strongest bounds on WDM, and the most precise measurement of subhalo abundance around strong lenses. Further improvements will follow from the large sample of lenses to be discovered by Euclid, Rubin, and Roman.

  PublisherOA PDFDOI

• Cosmic structure strikes back: The elimination of vector-mediated nonstandard interaction models as a mechanism for sterile neutrino dark matter production

  Physical review. D/Physical review. D. · 2025-11-08 · 1 citations

  articleOpen accessSenior author

  We revisit sterile neutrino production enabled by nonstandard interactions (NSIs) among active neutrinos mediated by new bosons. We focus on vector mediators, including neutrinophilic, gauged <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:msub> <a:mrow> <a:mi>L</a:mi> </a:mrow> <a:mrow> <a:mi>μ</a:mi> </a:mrow> </a:msub> <a:mo>−</a:mo> <a:msub> <a:mrow> <a:mi>L</a:mi> </a:mrow> <a:mrow> <a:mi>τ</a:mi> </a:mrow> </a:msub> </a:mrow> </a:math> , and <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mrow> <c:mi>B</c:mi> <c:mo>−</c:mo> <c:mi>L</c:mi> </c:mrow> </c:math> realizations, that modify in-medium dispersion and scattering, thereby altering the active-sterile conversion history. Building on a novel production framework with NSI thermal potentials and collision integrals, we compute nonthermal phase-space distributions across sterile neutrino mixing and NSI parameters and map each point to an particle mass <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:msub> <e:mi>m</e:mi> <e:mi>th</e:mi> </e:msub> </e:math> via linear theory transfer function fitting with the cosmological structure formation Boltzmann solver. This enables a direct reinterpretation of state-of-the-art structure formation limits from Milky Way satellites, strong lensing, and the Lyman- <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi>α</g:mi> </g:math> forest. These limits, in conjunction with x-ray decay searches, as well as results from a wide variety of particle physics experiments allow for a more complete examination of these models. We find that these vector-mediated models are ruled out when the full combination of current constraints, listed above, are taken into account. NSI scalar-mediated models and models with low reheating temperatures remain viable.

  PublisherDOI

• Return of the Lepton Number: Sterile Neutrino Dark Matter Production and the Revival of the Shi-Fuller Mechanism

  ArXiv.org · 2025-07-24

  preprintOpen accessSenior author

  We explore resonant production of sterile neutrino dark matter via the Shi-Fuller (SF) mechanism, revisiting its cosmological viability in light of recent results demonstrating that lepton-number asymmetries $L_α\gtrsim 1$ at temperatures $T &gt; 20\rm\,MeV$ are consistent with big bang nucleosynthesis (BBN). Using a quasiclassical Boltzmann transport calculation of the dark matter production, we compute the nonthermal phase space distributions of sterile neutrinos across a broad range of particle mass $m_s$ and mixing angle $\sin^2{(2θ)}$ parameter space. We then evolve the resulting distributions through linear structure formation using CLASS and fit the resulting matter power spectra to thermal warm dark matter (WDM) transfer functions, enabling a direct mapping between SF models and equivalent thermal WDM particle masses $m_{\mathrm{th}}$. This allows us to reinterpret existing structure formation limits and Lyman-$α$ forest preferences in the context of SF production. We find that lepton asymmetries $L \gtrsim 0.5$ at high temperatures open significant viable parameter space in the $m_s \gtrsim 10\,\mathrm{keV}$ and $\sin^2 (2θ) \lesssim 10^{-14}$ regime, compatible with both x-ray constraints from NuSTAR and INTEGRAL/SPI and recent Lyman-$α$ inferences of $m_{\mathrm{th}} \approx 4.1\,\mathrm{keV}$. Following lepton number evolution below 20 MeV, we also specifically show that this lepton asymmetry parameter space is compatible with BBN and cosmic microwave background constraints. We present updated constraints, a refined $m_{\mathrm{th}}$ fitting function, and power-law approximations for $L$ across the parameter space. Our results motivate future x-ray observations targeting the $\sim\! 20\,\mathrm{keV}$ photon regime and testing of the $m_\mathrm{th} \gtrsim 10\,\mathrm{keV}$ WDM region.

  PublisherOA PDFDOI

• The Preference for Evolving Dark Energy from Cosmological Distance Measurements and Possible Signatures in the Growth Rate of Perturbations

  arXiv (Cornell University) · 2025-02-18 · 1 citations

  preprintOpen access

  In this study, we use a flexible parametrization of the equation of state of dark energy to explore its possible evolution with datasets from the Dark Energy Spectroscopic Instrument (DESI), Planck cosmic microwave background, and either the 5-year Dark Energy Survey (DES) or the Pantheon+ (PP) supernova (SN) compilation. This parametrization, called transitional dark energy, allows for rapid changes in the equation of state but also changes like that in the Chevallier-Polarski-Linder parametrization. We find a 3.8σ preference for evolving dark energy over ΛCDM with the DES dataset and a weaker 2.4σ preference when using the PP dataset. This corroborates the finding of the DESI Collaboration, who found that their baryon acoustic oscillation data preferred evolving dark energy when fit with the CPL parametrization of the equation of state. Our analysis reveals no significant outliers in the DESI data around the TDE best-fit, while the data is asymmetrically distributed around the ΛCDM best-fit model such that the measured distances are on average smaller. The DESI and SN data both prefer an expansion history that implies a higher dark energy density around z=0.5 than in the Planck-ΛCDM model, with the inferred equation of state being greater than -1 around z=0 and close to or below -1 at z&gt;0.5. We show that when the expansion rate is greater than that in the Planck-ΛCDM model (around z=0.5), the growth rate calculated assuming General Relativity is suppressed relative to the Planck-ΛCDM model, and it rebounds as the expansion rate differences between the models become smaller closer to the present time. The resulting flattening of the $fσ_8(z)$ curve compared to the ΛCDM model could be an independent signature of the temporal evolution of dark energy.

  PublisherOA PDFDOI

• Status of neutrino cosmology: Standard <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Λ</mml:mi><mml:mi>CDM</mml:mi></mml:mrow></mml:math>, extensions, and tensions

  Physical review. D/Physical review. D. · 2025-02-10 · 17 citations

  articleSenior author

  We examine the performance of the six-parameter $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model and its extensions in light of recent cosmological observations, with particular focus on neutrino properties inferred from cosmology. Using a broad suite of nine combinations of datasets, with three separate analyses of the Planck cosmic microwave background (CMB) data, and three separate survey datasets of supernovae (SNe), plus the recent DESI baryon acoustic oscillation (BAO) scale results, we derive constraints on the sum of neutrino masses ($\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$). Our results show upper limits in the range of $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}&lt;76.9\text{ }\text{ }\mathrm{meV}$ to $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}&lt;108\text{ }\text{ }\mathrm{meV}$ (95% CL). The variation in the limits on $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$ arises from the separate analyses of the Planck CMB data and the separate supernova datasets, as they relate to the inferred matter density and its relation to the sensitivity of the BAO scale and CMB lensing to $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$. In the context of hierarchical mass models in $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$, we find a $1.47\ensuremath{\sigma}$ preference for normal ordering (NO) over inverted ordering (IO), with similar values of preference across all datasets. Despite the strong constraints, an inclination toward the nonstandard massless neutrinos over NO remains weak at $1.36\ensuremath{\sigma}$. We find that a ``negative'' neutrino mass, inferred from the shape of the likelihood in the physical regime, $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}&gt;0$, is only present at less than $2\ensuremath{\sigma}$. The strong $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$ constraints originate primarily from the high CMB lensing signal, which disfavors the suppression of power from $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$, and the DESI BAO scale, which is complementary to that from the suppression of power. We confirm that models allowing extra relativistic degrees of freedom, with ${N}_{\mathrm{eff}}\ensuremath{\approx}3.5$, alleviate the Hubble tension. Significantly, we find a $3.3\ensuremath{\sigma}$ preference for a 0.1 eV partially thermalized sterile neutrino when the SH0ES ${H}_{0}$ measurement is included, a scale of interest in short-baseline oscillation experiment results. When ${H}_{0}$ is included, fully thermalized sterile neutrino models are as consistent as $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ in fitting all datasets, but are disfavored otherwise. We also explore an 11-parameter model relaxing the dark energy equation of state and curvature, together with $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$ and ${N}_{\mathrm{eff}}$, finding consistency with $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ parameters except for the dark energy equation of state, ${w}_{0}=\ensuremath{-}0.96{1}_{\ensuremath{-}0.037}^{+0.012}$. Neutrino mass constraints in this extended model remain stringent, with $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}&lt;97.0\text{ }\text{ }\mathrm{meV}$ (95% CL).

  PublisherDOI

Recent grants

• CAREER: Cosmological Structure at Small Scales; From the Nature of Dark Matter and its Small-Scale Behavior to Galaxy Formation

  NSF · $160k · 2010–2012

• Frontier Challenges in Neutrino Cosmology, Dark Energy and Dark Matter

  NSF · $75k · 2009–2011

• CAREER: Cosmological Structure at Small Scales; From the Nature of Dark Matter and its Small-Scale Behavior to Galaxy Formation

  NSF · $320k · 2011–2015

Frequent coauthors

• George M. Fuller

  University of California, San Diego

  35 shared

• Steve Blanchet

  École Polytechnique Fédérale de Lausanne

  32 shared

• J. P. Harding

  Los Alamos National Laboratory

  25 shared

• Scott Dodelson

  Carnegie Mellon University

  23 shared

• Shunsaku Horiuchi

  21 shared

• Joshua A. Frieman

  Fermi National Accelerator Laboratory

  20 shared

• Ryan E. Keeley

  20 shared

• Renée Hložek

  University of Toronto

  19 shared

Labs

• Eddleman Quantum InstitutePI

Education

• PhD, Physics

  University of California San Diego

  2001

• B.S., Physics

  University of Houston

  1996

Awards & honors

• Howard Lee awarded Humboldt Research Fellowship