15 papers
A lower bound on primordial power spectrum from halo substructure
Shin'ichiro Ando, Nagisa Hiroshima, Koji Ishiwata +1
We investigate how the primordial curvature perturbation of a certain wavelength scale affects the halo and subhalo structure. Primordial power spectrum considered in this paper fe…
Constraints on the VHE counterpart of two binary black hole mergers observed by the MAGIC and CTAO LST-1 telescopes
K. Abe, S. Abe, J. Abhir +439
We present very-high-energy gamma-ray observations of two binary black hole merger candidates, GW240615_113620 and GW241125_010116, performed with the Major Atmospheric Gamma Imagi…
Evading Cosmological Strong Coupling in Non-minimally Coupled Vector Gravity
Antonio De Felice, Seishi Enomoto, Nagisa Hiroshima +1
Recent analyses of Proca theories with non-minimal curvature couplings have uncovered an additional scalar degree of freedom with an identically vanishing propagation speed, $c_s^2…
Revisiting the limits on dark matter annihilation cross-section and decay lifetime in light of electron and positron fluxes
Nagisa Hiroshima, Kazunori Kohri, Partha Kumar Paul +1
We revisit the upper bound on the annihilation cross-section, of a stable dark matter (DM) of mass GeV by considering five different channels: $W^+…
Extreme Blazars Observed with MAGIC: Second Catalog Release
K. Abe, S. Abe, J. Abhir +353
Extremely high-peaked BL Lac objects - also named extreme blazars - are among the most energetic and persistent extragalactic accelerators in the Universe, defined by a synchrotron…
Chasing Gamma-Ray Signals from Binary Neutron Star Coalescences with the Cherenkov Telescope Array: Prospects and Observing Strategies
S. Abe, J. Abhir, A. Abhishek +457
The detection of gravitational waves (GWs) from a binary neutron star (BNS) merger by Advanced LIGO and Advanced Virgo (GW170817), together with its electromagnetic counterpart, th…