A5024368072- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Cold Atom Physics and Bose-Einstein Condensates
- Particle physics theoretical and experimental studies
- Laser-Plasma Interactions and Diagnostics
- Astrophysics and Cosmic Phenomena
- Advanced Frequency and Time Standards
- Particle Detector Development and Performance
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Black Holes and Theoretical Physics
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Literature: history, themes, analysis
- Scientific Research and Discoveries
- Quantum Information and Cryptography
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Shakespeare, Adaptation, and Literary Criticism
- Astronomy and Astrophysical Research
- Ionosphere and magnetosphere dynamics
- Quantum, superfluid, helium dynamics
- Galaxies: Formation, Evolution, Phenomena
- Empathy and Medical Education
Stanford University
2016-2025
Kavli Institute for Particle Astrophysics and Cosmology
2012-2025
Atomic Weapons Establishment
2008-2024
Virginia Tech
1980-2024
Menlo School
2008-2024
Sofia University
2024
CEA DAM Île-de-France
2014
General Atomics (United States)
2014
Massachusetts Institute of Technology
2014
Fusion Academy
2014
A new class of solutions to the electroweak hierarchy problem is presented that does not require either weak scale dynamics or anthropics. Dynamical evolution during early universe drives Higgs mass a value much smaller than cutoff. The simplest model has particle content standard plus QCD axion and an inflation sector. highest cutoff achieved in any technically natural 10^8 GeV.
We propose an experiment to search for QCD axion and axionlike-particle dark matter. Nuclei that are interacting with the background matter acquire time-varying CP-odd nuclear moments such as electric dipole moment. In analogy magnetic resonance, these cause precession of spins in a material sample presence field. Precision magnetometry can be used precession. An initial phase this could cover many orders magnitude parameter space beyond current astrophysical laboratory limits. And...
We calculate the production of a massive vector boson by quantum fluctuations during inflation. This gives novel dark-matter mechanism quite distinct from misalignment or thermal production. While scalars and tensors are typically produced with nearly scale-invariant spectrum, surprisingly is power spectrum peaked at intermediate wavelengths. Thus dangerous, long-wavelength, isocurvature perturbations suppressed. Further, long wavelengths inherits usual adiabatic, inflaton, allowing it to be...
Four decades after its prediction, the axion remains most compelling solution to Strong-CP problem and a well-motivated dark matter candidate, inspiring host of elegant ultrasensitive experiments based on axion-photon mixing. This report reviews experimental situation several fronts. The microwave cavity experiment is making excellent progress in search for axions microelectronvolt range may be plausibly extended up 100 mu eV. Within past years however, it has been realized that are...
We propose new signals for the direct detection of ultralight dark matter such as axion. Axion or axion like particle (ALP) may be thought a background, classical field. consider couplings this field which give rise to observable effects including nuclear electric dipole moment, and axial nucleon electron moments. These moments oscillate rapidly with frequencies accessible in laboratory, ~ kHz GHz, given by mass. Thus, contrast WIMP detection, instead searching hard scattering single...
The unprecedented precision of atom interferometry will soon lead to laboratory tests general relativity levels that rival or exceed those reached by astrophysical observations. We propose such an experiment initially test the equivalence principle 1 part in 10(15) (300 times better than current limit), and 10(17) future. It also probe relativistic effects - as nonlinear three-graviton coupling, gravity atom's kinetic energy, falling light several decimals. In contrast with observations, can...
Laser frequency noise is a dominant background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration this requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, example, two satellites space-based detector or arms ground-based detector. We describe new strategy based recent advances in atomic clocks and atom interferometry which can operate at long baselines immune to laser noise. suppressed because...
We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite based, utilizing the core technology of Stanford 10 m presently under construction. Each configuration compares widely separated interferometers run using common lasers. The signal scales with distance between interferometers, which can be large since only light travels over this distance, not atoms. experiment $\ensuremath{\sim}10\text{ }\text{ }\mathrm{m}$ by a...
Abstract We propose in this White Paper a concept for space experiment using cold atoms to search ultra-light dark matter, and detect gravitational waves the frequency range between most sensitive ranges of LISA terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment Dark Matter Gravity Exploration (AEDGE), will also complement other planned searches exploit synergies with wave detectors. give examples extended sensitivity matter offered...
The mass of the dark matter particle is unknown, and may be as low $\ensuremath{\sim}1{0}^{\ensuremath{-}22}\text{ }\text{ }\mathrm{eV}$. lighter part this range, below $\ensuremath{\sim}\mathrm{eV}$, relatively unexplored both theoretically experimentally but contains an array natural candidates. An example relaxion, a light boson predicted by cosmological solutions to hierarchy problem. One few generic signals such can produce time-oscillating, equivalence-principle-violating force. We...
The transit of primordial black holes through a white dwarf causes localized heating around the trajectory hole dynamical friction. For sufficiently massive holes, this heat can initiate runaway thermonuclear fusion causing to explode as supernova. shape observed distribution dwarfs with masses up $1.25{M}_{\ensuremath{\bigodot}}$ rules out $\ensuremath{\sim}{10}^{19}--{10}^{20}\text{ }\text{ }\mathrm{gm}$ dominant constituent local dark matter density. Black large ${10}^{24}\text{ will be...
MAGIS-100 is a next-generation quantum sensor under construction at Fermilab that aims to explore fundamental physics with atom interferometry over 100-meter baseline. This novel detector will search for ultralight dark matter, test mechanics in new regimes, and serve as technology pathfinder future gravitational wave detectors previously unexplored frequency band. It combines techniques demonstrated state-of-the-art 10-meter-scale interferometers the latest technological advances of world's...
For the minimal QCD axion model it is generally believed that overproduction of dark matter constrains mass to be above a certain threshold, or at least initial misalignment angle must tuned if below threshold. We demonstrate this incorrect. During inflation, Hubble scale low, tends toward an equilibrium. This means can naturally give observed abundance in entire lower part range, down masses $\sim 10^{-12}$ eV (or $f_a$ up almost Planck scale). The generated by quantum fluctuations field...
Models in which dark matter consists entirely of primordial black holes (PBHs) with masses around $10^{17}$ g are currently unconstrained. However, if PBHs a component the Galactic density, they will inject large flux energetic particles into Galaxy as radiate. Positrons produced by these subsequently propagate throughout and annihilate, contributing to 511 keV line. Using measurements this line INTEGRAL satellite constraint on PBH positron injection, we place new limits abundance mass range...
Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the nonrelativistic calculation phase shift in an atom interferometer and deriving its range validity. From this, we develop a method for calculating Both atoms light are treated relativistically all coordinate dependencies removed, thus revealing novel terms, cancellations, new origins previously calculated terms. This formalism then used find relativistic...
We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon can be described as weakly coupled ``hidden electric field,'' oscillating at frequency fixed by the mass, and able penetrate any shielding. At low frequencies (compared inverse size shielding), we find that observable effect hidden photon inside shielding is real, magnetic field. outline experimental setups designed matter, using tunable, LC circuit couple...
Dark sectors, consisting of new, light, weakly-coupled particles that do not interact with the known strong, weak, or electromagnetic forces, are a particularly compelling possibility for new physics. Nature may contain numerous dark each their own beautiful structure, distinct particles, and forces. This review summarizes physics motivation sectors exciting opportunities experimental exploration. It is summary Intensity Frontier subgroup "New, Light, Weakly-coupled Particles" Community...
We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of Stanford 10 m presently under construction. The experiment can operate with strain sensitivity ∼10−19Hz in 1–10 Hz band, inaccessible to LIGO, detect waves from solar mass binaries out megaparsec distances. satellite probes same frequency spectrum as LISA comparable ∼10−20Hz. Each configuration compares widely separated interferometers run...
Current techniques cannot detect axion dark matter over much of its parameter space, particularly in the theoretically well-motivated region where decay constant f_a lies near GUT and Planck scales. We suggest a novel experimental method to search for QCD this region. The field oscillates at frequency equal mass when it is component matter. These oscillations induce time varying CP-odd nuclear moments, such as electric dipole Schiff moments. coupling between internal atomic fields these...
We show that gravitational wave detectors based on a type of atom interferometry are sensitive to ultralight scalar dark matter. Such matter can cause temporal oscillations in fundamental constants with frequency set by the mass and amplitude determined local density. The result is modulation atomic transition energies. point out new time-domain signature this effect detector compares two spatially separated interferometers referenced common laser. improve current searches for electron-mass...
Traditional ideas for testing unification involve searching the decay of proton and its branching modes. We point out that several astrophysical experiments are now reaching sensitivities allow them to explore supersymmetric unified theories. In these theories electroweak-mass dark matter particle can decay, just like proton, through dimension 6 operators with lifetime $\ensuremath{\sim}{10}^{26}\text{ }\text{ }\mathrm{s}$. Interestingly, this time scale is being investigated in including...
We point out two ways to search for low-mass axion dark matter using cosmic microwave background (CMB) polarization measurements. These appear, in particular, be some of the most promising directly detect fuzzy matter. Axion causes rotation light passing through it. This gives rise novel phenomena CMB. First, late-time oscillations field today cause CMB oscillate phase across entire sky. Second, early-time wash produced at last-scattering, reducing polarized fraction (TE and EE power...
We report the results of a search for axionlike dark matter using nuclear magnetic resonance (NMR) techniques. This is part multi-faceted Cosmic Axion Spin Precession Experiment (CASPEr) program. In order to distinguish from fields, we employ comagnetometry scheme measuring ultralow-field NMR signals involving two different nuclei ($^{13}$C and $^{1}$H) in liquid-state sample acetonitrile-2-$^{13}$C ($^{13}$CH$_{3}$CN). No signal was detected above background. result constrains parameter...
The existence of dark matter (DM) was first noticed by Zwicky in the 1930s, but its nature remains one great unsolved problems physics. A variety observations indicate that it is non-baryonic and non-relativistic. One preferred candidates for DM a weakly interacting massive particle (WIMP) most models stable. WIMP self-annihilation can produce cosmic rays, gamma other particles with signatures may be detectable. Hints anomalous cosmic-ray spectra found recent experiments, such as PAMELA,...