Hidden-sector dark matter achieves standard thermal relic abundance via early decoupling with temperature-matched freeze-out, enabling WIMP-like cross sections without late-time thermalization.
Dark Matter Annihilation in The Galactic Center As Seen by the Fermi Gamma Ray Space Telescope
7 Pith papers cite this work. Polarity classification is still indexing.
abstract
We analyze the first two years of data from the Fermi Gamma Ray Space Telescope from the direction of the inner 10 degrees around the Galactic Center with the intention of constraining, or finding evidence of, annihilating dark matter. We find that the morphology and spectrum of the emission between 1.25 degrees and 10 degrees from the Galactic Center is well described by a the processes of decaying pions produced in cosmic ray collisions with gas, and the inverse Compton scattering of cosmic ray electrons in both the disk and bulge of the Inner Galaxy, along with gamma rays from known points sources in the region. The observed spectrum and morphology of the emission within approximately 1.25 degrees (~175 parsecs) of the Galactic Center, in contrast, departs from the expectations for by these processes. Instead, we find an additional component of gamma ray emission that is highly concentrated around the Galactic Center. The observed morphology of this component is consistent with that predicted from annihilating dark matter with a cusped (and possibly adiabatically contracted) halo distribution (density proportional to r^{-gamma}, with gamma=1.18 to 1.33). The observed spectrum of this component, which peaks at energies between 1-4 GeV (in E^2 units), can be well fit by a 7-10 GeV dark matter particle annihilating primarily to tau leptons with a cross section in the range of 4.6 x 10^-27 to 5.3 x 10^-26 cm^3/s, depending on how the dark matter distribution is normalized. We also discuss other sources for this emission, including the possibility that much of it originates from the Milky Way's supermassive black hole.
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Cosmic ray protons scattering off dark matter produce the Galactic Center gamma-ray excess through inelastic up-scattering followed by decay or direct elastic 2-to-3 photon production.
Paleo-detectors can achieve high sensitivity to sub-GeV dark matter boosted by cosmic rays and supernovae, covering previously inaccessible parameter space with orders of magnitude better reach than current experiments.
A differentiable forward model and likelihood enable probabilistic inference over many spatial morphologies for the Galactic Center gamma-ray Excess using variational methods on GPUs.
Refined Fermi-LAT analysis finds the Galactic Center Excess has a centrally concentrated spherical morphology consistent with generalized Navarro-Frenk-White inner slope ~1.15, significant across interstellar emission models, with spectrum peaking at a few GeV and upper limits above tens of GeV.
WIMP models for the Galactic Center Excess survive only in finely tuned resonant funnels with portal couplings around 10^-4, with leptophilic vectors and pseudoscalar portals remaining most viable after current bounds.
Projects COSI and AMEGO-X sensitivities to sub-GeV DM in vector-scalar portals, finding COSI leading in some regions beyond CMB limits and AMEGO-X covering most continuum cases.
citing papers explorer
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WIMP-like Dark Matter Without Thermalization At Freeze-Out
Hidden-sector dark matter achieves standard thermal relic abundance via early decoupling with temperature-matched freeze-out, enabling WIMP-like cross sections without late-time thermalization.
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Producing the GeV Galactic Center Excess via Cosmic Ray-Dark Matter Scattering
Cosmic ray protons scattering off dark matter produce the Galactic Center gamma-ray excess through inelastic up-scattering followed by decay or direct elastic 2-to-3 photon production.
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Probing Cosmic-Ray-Boosted and Supernova-Sourced Sub-GeV Dark Matter with Paleo-Detectors
Paleo-detectors can achieve high sensitivity to sub-GeV dark matter boosted by cosmic rays and supernovae, covering previously inaccessible parameter space with orders of magnitude better reach than current experiments.
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High-dimensional inference for the $\gamma$-ray sky with differentiable programming
A differentiable forward model and likelihood enable probabilistic inference over many spatial morphologies for the Galactic Center gamma-ray Excess using variational methods on GPUs.
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A Precise Measurement of the Fermi-LAT Galactic Center Excess Morphology and Spectrum
Refined Fermi-LAT analysis finds the Galactic Center Excess has a centrally concentrated spherical morphology consistent with generalized Navarro-Frenk-White inner slope ~1.15, significant across interstellar emission models, with spectrum peaking at a few GeV and upper limits above tens of GeV.
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A Comprehensive Study of WIMP Models Explaining the Fermi-LAT Galactic Center Excess
WIMP models for the Galactic Center Excess survive only in finely tuned resonant funnels with portal couplings around 10^-4, with leptophilic vectors and pseudoscalar portals remaining most viable after current bounds.
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Constraining light dark matter in vector-scalar portals with COSI and AMEGO-X
Projects COSI and AMEGO-X sensitivities to sub-GeV DM in vector-scalar portals, finding COSI leading in some regions beyond CMB limits and AMEGO-X covering most continuum cases.