334 citations · 4k across the 75 of their papers we have counts for
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Primordial Black Holes and Local Non-Gaussianity in Canonical Inflation
Samuel Passaglia, Wayne Hu, Hayato Motohashi
Primordial black holes (PBHs) cannot be produced abundantly enough to be the dark matter in canonical single-field inflation under slow roll. This conclusion is robust to local non…
Stealth Schwarzschild solution in shift symmetry breaking theories
Masato Minamitsuji, Hayato Motohashi
We find stealth Schwarzschild solutions with a nontrivial profile of the scalar field regular on the horizon in the Einstein gravity coupled to the scalar field with the k-essence…
Shape dependence of spontaneous scalarization
Hayato Motohashi, Shinji Mukohyama
Spontaneous scalarization is an interesting mechanism for modification of gravity by nonminimal coupling of a scalar field to matter or curvature invariants in the context of scala…
Ghost-free theories with arbitrary higher-order time derivatives
Hayato Motohashi, Teruaki Suyama, Masahide Yamaguchi
We construct no-ghost theories of analytic mechanics involving arbitrary higher-order derivatives in Lagrangian. It has been known that for theories involving at most second-order…
General Relativity solutions in modified gravity
Hayato Motohashi, Masato Minamitsuji
Recent gravitational wave observations of binary black hole mergers and a binary neutron star merger by LIGO and Virgo Collaborations associated with its optical counterpart constr…
Reconciling tensor and scalar observables in G-inflation
Héctor Ramírez, Samuel Passaglia, Hayato Motohashi +2
The simple potential as an inflationary model is coming under increasing tension with limits on the tensor-to-scalar ratio and measurements of the scalar spectral inde…