A5083960669- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Computational Physics and Python Applications
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Radioactive Decay and Measurement Techniques
- Scientific Research and Discoveries
- Noncommutative and Quantum Gravity Theories
- Gamma-ray bursts and supernovae
- Relativity and Gravitational Theory
- High-Energy Particle Collisions Research
- History and Developments in Astronomy
- VLSI and Analog Circuit Testing
- Radio Astronomy Observations and Technology
- Low-power high-performance VLSI design
- Age of Information Optimization
- Adaptive optics and wavefront sensing
New York University
2015-2025
Flatiron Institute
2018
Flatiron Health (United States)
2018
Institute for Advanced Study
2011-2013
Albert Einstein College of Medicine
2011
Williams College
2005
University of Washington
2001-2004
Boston University
2004
Motorola (United States)
2002
University of California, Berkeley
1989-2001
We propose a comprehensive theory of dark matter that explains the recent proliferation unexpected observations in high-energy astrophysics. Cosmic ray spectra from ATIC and PAMELA require WIMP (weakly interacting massive particle). with mass ${M}_{\ensuremath{\chi}}\ensuremath{\sim}500--800\text{ }\text{ }\mathrm{GeV}$ annihilates into leptons at level well above expected thermal relic. Signals WMAP EGRET reinforce this interpretation. Limits on $\overline{p}$...
Many observations suggest that much of the matter universe is nonbaryonic. Recently, DAMA NaI dark direct detection experiment reported an annual modulation in their event rate consistent with a WIMP relic. However, Cryogenic Dark Matter Search (CDMS) Ge excludes most region preferred by DAMA. We demonstrate if can only scatter making transition to slightly heavier state $(\ensuremath{\Delta}m\ensuremath{\sim}100 \mathrm{keV}),$ experiments are no longer conflict. Moreover, differences...
We show that mass varying neutrinos (MaVaNs) can behave as a negative pressure fluid which could be the origin of cosmic acceleration. derive model independent relation between neutrino and equation state parameter dark energy, is applicable for general theories particles. The depends on local density observed exceed cosmological bound constant mass. discuss microscopic realizations MaVaN acceleration scenario, involve sterile neutrino. consider naturalness constraints particles, find both...
We show that cold dark matter particles interacting through a Yukawa potential could naturally explain the recently observed cores in dwarf galaxies without affecting dynamics of objects with much larger velocity dispersion, such as clusters galaxies. The dependence associated cross section well possible exothermic nature interaction alleviates earlier concerns about strongly matter. Dark evaporation low-mass might deficit satellite Milky Way halo and have important implications for first...
We propose a dark matter candidate with an ``excited state'' 1--2 MeV above the ground state, which may be collisionally excited and deexcites by ${e}^{+}{e}^{\ensuremath{-}}$ pair emission. By converting its kinetic energy into pairs, such particle could produce substantial fraction of 511 keV line observed International Gamma-Ray Astrophysics Laboratory/SPI in inner Milky Way. Only small candidates have sufficient to excite, that drops sharply galactocentric radius, naturally yielding...
The Fermi Gamma-Ray Space Telescope reveals a diffuse inverse Compton signal in the inner Galaxy with similar spatial morphology to microwave haze observed by WMAP, supporting synchrotron interpretation of signal. Using templates, we regress out pi0 gammas, as well IC and bremsstrahlung components associated known soft-synchrotron counterparts. We find significant gamma-ray excess towards Galactic center spectrum that is significantly harder than other sky most consistent from hard...
This document a outlines set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these have when applied searches at LHC, provide number useful expressions reference. The list includes both s-channel t-channel scenarios. For s-channel, spin-0 spin-1 mediations are discussed, also realizations where Higgs particle provides portal between visible sectors. guiding principles underpinning proposed...
As cosmological data have improved, tensions arisen. One such tension is the difference between locally measured Hubble constant $H_0$ and value inferred from cosmic microwave background (CMB). Interacting radiation has been suggested as a solution, but studies show that conventional models are precluded by high-$\ell$ CMB polarization data. It seems at least plausible solution may be provided related distinguish high- low-$\ell$ multipoles. When interactions of strongly-coupled mediated...
What is the form of neutrino mass matrix which governs oscillations atmospheric and solar neutrinos? Features data have led to a dominant viewpoint where has an ordered, regulated pattern, perhaps dictated by flavor symmetry. We challenge this demonstrate that are well accounted for appears random entries.
In light of recent positive results from the DAMA experiment, as well new null CDMS Soudan, Edelweiss, ZEPLIN-I and CRESST, we reexamine framework inelastic dark matter with a standard halo. this framework, which was originally introduced to reconcile tensions between DAMA, particles can scatter off nuclei only by making transition nearly degenerate state that is roughly $100 \kev$ heavier. We find data significantly constrains parameter space but there are still regions consistent all...
We propose a new solution to the supersymmetric flavor problem without flavor-blind mediation. Our proposal is enforce continuous or suitably large discrete R-symmetry on weak scale supersymmetry, so that Majorana gaugino masses, trilinear A-terms, and mu-term are forbidden. find replacing MSSM with an R-symmetric model allows order one flavor-violating soft even for squarks of few hundred GeV. The minimal contains Dirac masses Higgsino no left-right mixing in squark slepton sector. TeV...
The velocity distribution function of dark matter particles is expected to show significant departures from a Maxwell-Boltzmann distribution. This can have profound effects on the predicted - nucleon scattering rates in direct detection experiments, especially for models which sensitive high tail distribution, such as inelastic (iDM) or light (few GeV) (LDM), and experiments that require energy recoil events, many directionally experiments. Here we determine functions two highest resolution...
Inelastic dark matter, in which weakly interacting massive particle (WIMP)-nucleus scatterings occur through a transition to an excited WIMP state $\ensuremath{\sim}100\text{ }\text{ }\mathrm{keV}$ above the ground state, provides compelling explanation of DAMA annual modulation signal. We demonstrate that relative sensitivities various matter direct detection experiments are modified such signal can be reconciled with absence reported at CDMS-Soudan, XENON10, ZEPLIN, CRESST, and KIMS for...
Recently, the CoGeNT experiment has reported events in excess of expected background. We analyze dark matter scenarios which can potentially explain this signal. Under standard case spin independent scattering with equal couplings to protons and neutrons, we find significant tensions existing constraints. Consistency these limits is possible if a large fraction putative signal coming from an additional source experimental In case, recoils cannot be said excess, but are consistent it. also...
We consider a class of theories in which neutrino masses depend significantly on environment, as result interactions with the dark sector. Such mass varying neutrinos were recently introduced to explain origin cosmological energy density and why its magnitude is apparently coincidental that splittings. In this Letter we argue such can exhibit different matter vacuum, dramatically affecting oscillations. As an example modifications standard picture, simple models may simultaneously account...
Underground searches for dark matter involve a complicated interplay of particle physics, nuclear atomic physics and astrophysics. We attempt to remove the uncertainties associated with astrophysics by developing means map observed signal in one experiment directly into predicted rate at another. argue that it is possible make experimental comparisons are completely free astrophysical focusing on {\em integral} quantities, such as $g(v_{min})=\int_{v_{min}} dv\, f(v)/v $ $\int_{v_{thresh}} v...
Multiple lines of evidence indicate an anomalous injection high-energy ${e}^{+}{e}^{\ensuremath{-}}$ in the galactic halo. The recent ${e}^{+}$ fraction spectrum from payload for antimatter matter exploration and light-nuclei astrophysics (PAMELA) shows a sharp rise up to 100 GeV. Fermi gamma-ray space telescope has found significant hardening cosmic-ray above GeV, with break, confirmed by HESS at around 1 TeV. advanced thin ionization calorimeter (ATIC) also detected similar excess, falling...
This review summarizes the motivations for and phenomenological consequences of nonstandard Higgs boson decays, with emphasis on final states containing a pair non-Standard-Model particles that subsequently decay to Standard Model particles. Typically these are part ``hidden'' sector, example neutral bosons or unstable neutralinos. We emphasize such decays allow substantially below LEP limit 114 GeV. in turn means ``fine-tuning'' problems many Beyond (BSM) theories, particular supersymmetric...
Results from the PAMELA experiment indicate presence of an excess cosmic ray positrons above 10 GeV. In this paper, we consider possibility that signal is result dark matter annihilations taking place in halo Milky Way. Rather than focusing on a specific particle physics model, take phenomenological approach and variety masses two-body annihilation modes, including ${W}^{+}{W}^{\ensuremath{-}}$, ${Z}^{0}{Z}^{0}$, $b\overline{b}$, ${\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$,...
Iodine is distinguished from other elements used in dark matter direct detection experiments both by its large mass as well magnetic moment. Inelastic utilizes the of iodine to allay tensions between DAMA annual modulation signature and null results experiments. We explore models inelastic that also take advantage second distinct property iodine, namely In such couplings are augmented magnetic, rather than merely electric, interactions. These provide simple examples where signal compatible...
The effective interactions of dark matter with photons are fairly restricted. Yet both direct detection as well monochromatic gamma ray signatures depend sensitively on the presence such interactions. For a Dirac fermion, electromagnetic dipoles possible, but very constrained. Majorana fermions, no terms allowed. We consider signals an theory particle and its couplings to photons. In nearby excited state, there is possibility magnetic dipole transition (Magnetic inelastic Dark Matter or...
A bstract The QCD axion is one of the most compelling solutions strong CP problem. There are major current efforts into searching for an ultralight, invisible axion, which believed to be only phenomenologically viable realization axion. Visible axions with decay constants at or below electroweak scale have been long excluded by laboratory searches. Considering significance solution problem, we revisit experimental constraints on in $$ \mathcal{O} <mml:math...