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1. Beyond Hawking evaporation of black holes formed by dark matter in compact stars

   https://doi.org/10.1103/PhysRevD.111.L041306  

   Basumatary, Ujjwal; Raj, Nirmal; Ray, Anupam (February 2025, Physical Review D)

   The memory burden effect is an explicit resolution to the information paradox by which an evaporating black hole acquires quantum hair, which then suppresses its rate of mass loss with respect to the semiclassical Hawking rate. We show that this has significant implications for particle dark matter that captures in neutron stars and forms black holes that go on to consume the host star. In particular, we show that constraints on the nucleon scattering cross section and mass of spin-0 and spin- $1/2$dark matter would be extended by several orders of magnitude. Published by the American Physical Society2025 

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2. Standard model $CP$ violation is enough

   https://doi.org/10.1103/glgl-v4v6  

   Elor, Gilly; Houtz, Rachel; Ipek, Seyda; Ulloa, Martha (July 2025, Physical Review D)

   Is the standard model charge-parity ( $CP$) violation ever enough to generate the observed baryon asymmetry? Yes! We introduce a mechanism of baryogenesis (and dark matter production) that can generate the entire observed baryon asymmetry of the Universe using the $CP$violation within standard model systems—a feat which no other mechanism currently proposed can achieve. Baryogenesis proceeds through a mesogenesis scenario but with well motivated additional dark sector dynamics: a field generates present day mass contributions for the particle mediating the decay responsible for baryogenesis. The effect is an enhancement of baryon production while evading present day collider constraints. The $CP$violation comes entirely from standard model contributions to neutral meson systems. Meanwhile, the dark dynamics generate gravitational waves that may be searched for with current and upcoming pulsar timing arrays, as we demonstrate with an example potential that is tuned to generate domain walls that annihilate later. This mechanism, , motivates probing a new parameter space as well as improving the sensitivity of existing mesogenesis searches at hadron and electron colliders. Published by the American Physical Society2025 

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3. Probing light dark matter through cosmic-ray cooling in active galactic nuclei

   https://doi.org/10.1103/PhysRevD.110.L011701  

   Herrera, Gonzalo; Murase, Kohta (July 2024, Physical Review D)

   Recent observations of high-energy neutrinos from active galactic nuclei (AGN), NGC 1068 and TXS $0506+056$, suggest that cosmic rays (CRs) are accelerated in the vicinity of the central supermassive black hole and high-energy protons and electrons can cool efficiently via interactions with ambient photons and gas. The dark matter density may be significantly enhanced near the black hole, and CRs could lose energies predominantly due to scatterings with the ambient dark matter particles. We propose CR cooling in AGN as a new probe of dark matter-proton and dark matter-electron scatterings. Under plausible astrophysical assumptions, our constraints on sub-GeV dark matter can be the strongest derived to date. Some of the parameter space favored by thermal light dark matter models might already be probed with current multimessenger observations of AGN. Published by the American Physical Society2024 

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4. Cosmological constraints on dark neutrino towers

   https://doi.org/10.1103/PhysRevD.111.015024  

   Anchordoqui, Luis A; Antoniadis, Ignatios; Lüst, Dieter; Peñaló_Castillo, Karem (January 2025, Physical Review D)

   We reexamine a dynamical dark matter model with Kaluza-Klein (KK) towers of gravitons and neutrinos fitting together in the dark dimension. We show that even though gravitational decays of neutrino KK towers have little impact in cosmology, the weak decay channel could have significant cosmological effects. Taking conservative upper bounds on the dark matter decay rate into two photons before reionization and on the number of effective extra neutrino species $\mathrm{\Delta }{N}_{\mathrm{eff}}$, we derive constraints on the conversion rate from active to sterile species despite the dependence of the mixing angle on the KK mode mass. We also provide counterarguments to a recent claim suggesting that the bounds on $\mathrm{\Delta }{N}_{\mathrm{eff}}$rule out micron-sized extra dimensions. Published by the American Physical Society2025 

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5. Dark matter catalyzed baryon destruction

   https://doi.org/10.1103/PhysRevD.111.023005  

   Ema, Yohei; McGehee, Robert; Pospelov, Maxim; Ray, Anupam (January 2025, Physical Review D)

   WIMP-type dark matter may have additional interactions that break baryon number, leading to induced nucleon decays which are subject to direct experimental constraints from proton decay experiments. In this work, we analyze the possibility of continuous baryon destruction, deriving strong limits from the dark matter accumulating inside old neutron stars, as such a process leads to excess heat generation. We construct the simplest particle dark matter model that breaks the baryon and lepton numbers separately but conserves $B-L$. Virtual exchange by DM particles in this model results in dinucleon decay via $nn\to n\overline{\nu }$and $np\to n{e}^{+}$processes. Published by the American Physical Society2025 

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