Refereed papers

[69]
''Exact solution for rotating black holes in parity-violating gravity'',
Hiroaki W. H. Tahara, Kazufumi Takahashi, Masato Minamitsuji, Hayato Motohashi,
[arXiv:2312.11899].
[68]
''Iterative extraction of overtones from black hole ringdown'',
Kazuto Takahashi, Hayato Motohashi,
[arXiv:2311.12762].
[67]
''Black hole ringdown from physically sensible initial value problem in higher-order scalar-tensor theories'',
Keisuke Nakashi, Masashi Kimura, Hayato Motohashi, Kazufumi Takahashi,
Phys. Rev. D 109, 024034, [arXiv:2310.09839].
[66]
''Effective description of generalized disformal theories'',
Kazufumi Takahashi, Masato Minamitsuji, Hayato Motohashi,
JCAP 07 (2023) 009, [arXiv:2304.08624].
[65]
''Squeezed bispectrum and one-loop corrections in transient constant-roll inflation'',
Hayato Motohashi, Yuichiro Tada
JCAP 08 (2023) 069, [arXiv:2303.16035].
[64]
''Consistency of matter coupling in modified gravity'',
Kazufumi Takahashi, Rampei Kimura, Hayato Motohashi,
Phys. Rev. D 107, 044018 (2023), [arXiv:2212.13391].
[63]
''Differentiation identities for hypergeometric functions'',
[62]
''Physical effects of gravitational waves: pedagogical examples'',
Hayato Motohashi, Teruaki Suyama,
Eur. J. Phys. 44 (2023) 015601, [arXiv:2211.16955].
[61]
''Generalized disformal Horndeski theories: cosmological perturbations and consistent matter coupling'',
Kazufumi Takahashi, Masato Minamitsuji, Hayato Motohashi,
Prog. Theor. Exp. Phys. 2023, 013E01 (2023), [arXiv:2209.02176].
[60]
''Spectroscopy of Kerr-AdS5 spacetime with the Heun function: Quasinormal modes, greybody factor, and evaporation'',
Sousuke Noda, Hayato Motohashi,
Phys. Rev. D 106, 064025 (2022), [arXiv:2206.07721].
[59]
''Quasinormal modes of Schwarzschild black holes on the real axis'',
Koutarou Kyutoku, Hayato Motohashi, Takahiro Tanaka,
Phys. Rev. D 107, 044012 (2023), [arXiv:2206.00671].
[58]
''Evaporation of Echoing Black Holes'',
Naritaka Oshita, Hayato Motohashi, Sousuke Noda,
Phys. Rev. D 106, 044044 (2022), [arXiv:2205.15342].
[57]
''Black hole perturbations in higher-order scalar-tensor theories: initial value problem and dynamical stability'',
Keisuke Nakashi, Masashi Kimura, Hayato Motohashi, Kazufumi Takahashi,
Class. Quantum Grav. 39 (2022) 175003, [arXiv:2204.05054].
[56]
''Invertible disformal transformations with higher derivatives'',
Kazufumi Takahashi, Hayato Motohashi, Masato Minamitsuji,
Phys. Rev. D 105, 024015 (2022), [arXiv:2111.11634].
[55]
''Inflation with 0≤cs≤1'',
Mohammad Ali Gorji, Hayato Motohashi, Shinji Mukohyama,
JCAP 02 (2022) 030, [arXiv:2110.10731].
[54]
''Black hole perturbations in DHOST theories: Master variables, gradient instability, and strong coupling'',
Kazufumi Takahashi, Hayato Motohashi,
JCAP 08 (2021) 013, [arXiv:2106.07128].
[53]
''Exact solution for wave scattering from black holes: Formulation'',
[52]
''Stealth dark energy in scordatura DHOST theory'',
Mohammad Ali Gorji, Hayato Motohashi, Shinji Mukohyama,
JCAP 03 (2021) 081, [arXiv:2009.11606].
[51]
''On Rotating Black Holes in DHOST Theories'',
Jibril Ben Achour, Hongguang Liu, Hayato Motohashi, Shinji Mukohyama, Karim Noui,
JCAP 11 (2020) 001, [arXiv:2006.07245].
[50]
''General Relativity solutions with stealth scalar hair in quadratic higher-order scalar-tensor theories'',
Kazufumi Takahashi, Hayato Motohashi,
JCAP 06 (2020) 034, [arXiv:2004.03883].
[49]
''Effective Field Theory of Degenerate Higher-Order Inflation'',
[48]
''Ghost from constraints: a generalization of Ostrogradsky theorem'',
Katsuki Aoki, Hayato Motohashi,
JCAP 08 (2020) 026, [arXiv:2001.06756].
[47]
''Quantum Ostrogradsky theorem'',
Hayato Motohashi, Teruaki Suyama,
JHEP 2020, 32 (2020), [arXiv:2001.02483].
[46]
''Primordial Black Holes as Dark Matter through Higgs Criticality'',
Samuel Passaglia, Wayne Hu, Hayato Motohashi,
Phys. Rev. D 101, 123523 (2020), [arXiv:1912.02682].
[45]
''Weakly-coupled stealth solution in scordatura degenerate theory'',
Hayato Motohashi, Shinji Mukohyama,
JCAP 01 (2020) 030, [arXiv:1912.00378].
[44]
''Constant roll and primordial black holes'',
Hayato Motohashi, Shinji Mukohyama, Michele Oliosi,
JCAP 03 (2020) 002, [arXiv:1910.13235].
[43]
''Constant-roll inflation in scalar-tensor gravity'',
Hayato Motohashi, Alexei A. Starobinsky,
JCAP 11 (2019) 025, [arXiv:1909.10883].
[42]
''Linear stability analysis of hairy black holes in quadratic degenerate higher-order scalar-tensor theories: Odd-parity perturbations'',
Kazufumi Takahashi, Hayato Motohashi, Masato Minamitsuji,
Phys. Rev. D 100, 024041 (2019), [arXiv:1904.03554].
[41]
''Exact black hole solutions in shift-symmetric quadratic degenerate higher-order scalar-tensor theories'',
Hayato Motohashi, Masato Minamitsuji,
Phys.Rev. D 99, 064040 (2019), [arXiv:1901.04658].
[40]
''Primordial Black Holes and Local Non-Gaussianity in Canonical Inflation'',
Samuel Passaglia, Wayne Hu, Hayato Motohashi,
Phys.Rev. D 99, 043536 (2019), [arXiv:1812.08243].
[39]
''Shape dependence of spontaneous scalarization'',
Hayato Motohashi, Shinji Mukohyama,
Phys.Rev. D 99, 044030 (2019), [arXiv:1810.12691].
[38]
''Stealth Schwarzschild solution in shift symmetry breaking theories'',
Masato Minamitsuji, Hayato Motohashi,
Phys.Rev. D 98, 084027 (2018), [arXiv:1809.06611].
[37]
''Ghost-free theories with arbitrary higher-order time derivatives'',
Hayato Motohashi, Teruaki Suyama, Masahide Yamaguchi,
JHEP 1806 (2018) 133, [arXiv:1804.07990].
[36]
''General Relativity solutions in modified gravity'',
Hayato Motohashi, Masato Minamitsuji,
Phys.Lett. B781, 728-734 (2018), [arXiv:1804.01731].
[35]
''Reconciling tensor and scalar observables in G-inflation'',
Hector Ramirez, Samuel Passaglia, Hayato Motohashi, Wayne Hu, Olga Mena,
JCAP 1804 (2018) 04, 039, [arXiv:1802.04290].
[34]
''Ghost-free theory with third-order time derivatives'',
Hayato Motohashi, Teruaki Suyama, Masahide Yamaguchi,
J.Phys.Soc.Jpn. 87, 063401 (2018), [arXiv:1711.08125].
[33]
''Primordial Black Holes and Slow-Roll Violation'',
[32]
''f(R) constant-roll inflation'',
Hayato Motohashi, Alexei A. Starobinsky,
Eur.Phys.J. C77, 538 (2017), [arXiv:1704.08188].
[31]
''Generalized Slow Roll in the Unified Effective Field Theory of Inflation'',
[30]
''Constant-roll inflation: confrontation with recent observational data'',
Hayato Motohashi, Alexei A. Starobinsky,
Europhys. Lett. 117, 39001 (2017), [arXiv:1702.05847].
[29]
''General invertible transformation and physical degrees of freedom'',
Kazufumi Takahashi, Hayato Motohashi, Teruaki Suyama, Tsutomu Kobayashi,
Phys.Rev. D 95, 084053 (2017), [arXiv:1702.01849].
[28]
''Caustics for Spherical Waves'',
Claudia de Rham, Hayato Motohashi,
Phys.Rev. D95, 064008 (2017), [arXiv:1611.05038].
[27]
''Fundamental theorem on gauge fixing at the action level'',
Hayato Motohashi, Teruaki Suyama, Kazufumi Takahashi,
Phys.Rev. D94, 124021 (2016), [arXiv:1608.00071].
[26]
''Healthy degenerate theories with higher derivatives'',
Hayato Motohashi, Karim Noui, Teruaki Suyama, Masahide Yamaguchi, David Langlois,
JCAP 1607 (2016) 07, 033, [arXiv:1603.09355].
[25]
''Self-accelerating Massive Gravity: Hidden Constraints and Characteristics'',
Pavel Motloch, Wayne Hu, Hayato Motohashi,
Phys.Rev. D93, 104026 (2016), [arXiv:1603.03423].
[24]
''Nonlinear Excitations in Inflationary Power Spectra'',
V. Miranda, Wayne Hu, Chen He, Hayato Motohashi,
Phys.Rev. D93 (2016) 2, 023504, [arXiv:1510.07580].
[23]
''Self-accelerating Massive Gravity: Superluminality, Cauchy Surfaces and Strong Coupling'',
Pavel Motloch, Wayne Hu, Austin Joyce, Hayato Motohashi,
Phys.Rev. D92 (2015) 4, 044024, [arXiv:1505.03518].
[22]
''Disformal invariance of curvature perturbation'',
Hayato Motohashi, Jonathan White,
JCAP 1602 (2016) 02, 065, [arXiv:1504.00846].
[21]
''Running from Features: Optimized Evaluation of Inflationary Power Spectra'',
[20]
''Inflation with a constant rate of roll'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
JCAP 1509 (2015) 09, 018, [arXiv:1411.5021].
[19]
''Third-order equations of motion and the Ostrogradsky instability'',
Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D91 (2015) 8, 085009, [arXiv:1411.3721].
[18]
''Consistency relation for Rp inflation'',
[17]
''Stability of cosmological solutions in extended quasidilaton massive gravity'',
[16]
''Black hole perturbation in the most general scalar-tensor theory with second-order field equations II: the even-parity sector'',
Tsutomu Kobayashi, Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D 89, 084042 (2014), [arXiv:1402.6740].
[15]
''Constraint on reheating after f(R) inflation from gravitational waves'',
Atsushi Nishizawa, Hayato Motohashi,
Phys. Rev. D 89 (2014) 063541, [arXiv:1401.1023].
[14]
''Langevin description of gauged scalar fields in a thermal bath'',
Yuhei Miyamoto, Hayato Motohashi, Teruaki Suyama, Jun'ichi Yokoyama,
Phys. Rev. D 89, 085037 (2014), [arXiv:1308.4794].
[13]
''Cosmic string passage through the Earth by consequent global earthquake'',
[12]
''Ultra Slow-Roll Inflation and the non-Gaussianity Consistency Relation'',
Jerome Martin, Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D87 (2013) 023514, [arXiv:1211.0083].
[11]
''Consequences of a stochastic approach to the conformal invariance of inflationary correlators'',
Hayato Motohashi, Teruaki Suyama, Jun'ichi Yokoyama,
Phys. Rev. D86 (2012) 123514, [arXiv:1210.2497].
[10]
''Self-accelerating solutions in massive gravity on an isotropic reference metric'',
Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D 86, 081502(R) (2012), [arXiv:1208.3019].
[9]
''Reheating after f(R) inflation'',
Hayato Motohashi, Atsushi Nishizawa,
Phys. Rev. D 86, 083514 (2012), [arXiv:1204.1472].
[8]
''Cosmology Based on f(R) Gravity Admits 1 eV Sterile Neutrinos'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Phys. Rev. Lett. 110, 121302 (2013), [arXiv:1203.6828].
[7]
''Black hole perturbation in the most general scalar-tensor theory with second-order field equations I: the odd-parity sector'',
Tsutomu Kobayashi, Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D 85, 084025 (2012), Erratum: Phys.Rev. D96 (2017) no.10, 109903, [arXiv:1202.4893].
[6]
''Black hole perturbation in non-dynamical and dynamical Chern-Simons gravity'',
Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D 85, 044054 (2012), [arXiv:1110.6241].
[5]
''Black hole perturbation in parity violating gravitational theories'',
Hayato Motohashi, Teruaki Suyama,
Phys. Rev. D 84, 084041 (2011), [arXiv:1107.3705].
[4]
''Future Oscillations around Phantom Divide in f(R) Gravity'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
JCAP 1106 (2011) 006, [arXiv:1101.0744].
[3]
''Matter power spectrum in f(R) gravity with massive neutrinos'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Prog. Theor. Phys. 124: 541-546 (2010), [arXiv:1005.1171].
[2]
''Phantom boundary crossing and anomalous growth index of fluctuations in viable f(R) models of cosmic acceleration'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Prog. Theor. Phys. 123: 887-902 (2010), [arXiv:1002.1141].
[1]
''Analytic solution for matter density perturbations in a class of viable cosmological f(R) models'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Int. J. Mod. Phys. D 18: 1731-1740 (2009), [arXiv:0905.0730].

Non-refereed papers

[10]
''Black Hole Perturbation in Modified Gravity Theories '',
Hayato Motohashi, Tsutomu Kobayashi, Teruaki Suyama,
Proceedings of the 13th Marcel Grossmann Meeting Meeting on General Relativity,
C12-07-01.1, p.1295-1297, (2015).
[9]
''Reheating after f(R) inflation and observational constraints'',
Atsushi Nishizawa, Hayato Motohashi,
Proceedings of the 13th Marcel Grossmann Meeting Meeting on General Relativity,
C12-07-01.1, p. 1167-1169 (2015).
[8]
''Loop contribution to inflationary magnetic field'',
Hayato Motohashi, Teruaki Suyama,
arXiv:1401.1260.
[7]
''f(R) Cosmology and Massive Neutrinos'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Proceedings of CosPA 2011, Peking University,
Int. J. Mod. Phys. Conf. Ser. 10, 35 (2012).
[6]
''Joint description of inflation and dark energy in extended f(R) gravity'',
[5]
''Stability of Schwarzshild-like spacetime in parity violating gravitational theories'',
[4]
''f(R) Gravity and its Cosmological Implications'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Proceedings of 2nd International Workshop on Dark Matter, Dark Energy and Matter-Antimatter Asymmetry (2011),
Int.J.Mod.Phys. D20 (2011), pp. 1347-1355, [arXiv:1101.0716].
[3]
''Classification of Future Phantom-to-Normal Oscillations in f(R) Gravity'',
[2]
''Phantom behaviour and growth index anomalous evolution in viable f(R) gravity models'',
[1]
''Analytic solution for matter density fluctuations in f(R) models of cosmic acceleration'',
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama,
Proceedings of the 9th Asia-Pacific International Conference on Gravitation and Astrophysics, pp. 246-255 (2010).

Thesis

Doctor thesis (December, 2013)
''Cosmological consequences of modified gravity for the primordial and late-time cosmic acceleration''

Master thesis (December, 2010)
''An Approach for Dark Energy Problem by Modified Gravity Theory''
「修正重力理論によるダークエネルギー問題へのアプローチ」