237 citations · 1.8k across the 50 of their papers we have counts for
50 papers
Analytic Formulae for Inflationary Correlators with Dynamical Mass
Shuntaro Aoki, Toshifumi Noumi, Fumiya Sano +1
Massive fields can imprint unique oscillatory features on primordial correlation functions or inflationary correlators, which is dubbed the cosmological collider signal. In this wo…
Black Hole Extremality in Nonlinear Electrodynamics: A Lesson for Weak Gravity and Festina Lente Bounds
Yoshihiko Abe, Toshifumi Noumi, Kaho Yoshimura
We study black hole extremality in nonlinear electrodynamics motivated by the Weak Gravity Conjecture (WGC) and the Festina Lente (FL) bound. For illustration, we consider the Eule…
Gravitational Positivity for Phenomenologists: Dark Gauge Boson in the Swampland
Katsuki Aoki, Toshifumi Noumi, Ryo Saito +4
The gravitational positivity bound gives quantitative "swampland'' constraints on low-energy effective theories inside theories of quantum gravity. We give a comprehensive discussi…
Finite energy sum rules for gravitational Regge amplitudes
Toshifumi Noumi, Junsei Tokuda
We develop a framework to derive consistency constraints on gravitational Regge amplitudes based on the finite energy sum rules (FESRs), which directly connect gravitational Regge…
Higher derivative corrections to black brane thermodynamics and the weak gravity conjecture
Toshifumi Noumi, Hibiki Satake
We study higher derivative corrections to black brane thermodynamics and their implications for the weak gravity conjecture for -form gauge fields. In particular we show that hi…
Stability of Hairy Black Holes in Shift-Symmetric Scalar-Tensor Theories via the Effective Field Theory Approach
Justin Khoury, Toshifumi Noumi, Mark Trodden +1
Shift-symmetric Horndeski theories admit an interesting class of Schwarzschild-de Sitter black hole solutions exhibiting time-dependent scalar hair. The properties of these solutio…
Page curve and symmetries
Pak Hang Chris Lau, Toshifumi Noumi, Yuhei Takii +1
Motivated by the quantum process of black hole evaporation and its implications for symmetries, we consider a qubit system with a random dynamics as a toy model of black hole. We c…
Phenomenological Motivation for Gravitational Positivity Bounds: A Case Study of Dark Sector Physics
Toshifumi Noumi, Sota Sato, Junsei Tokuda
Positivity bounds on scattering amplitudes provide a necessary condition for a low-energy effective field theory to have a consistent ultraviolet completion. Their extension to gra…
Gravitational Positivity Bounds on Scalar Potentials
Toshifumi Noumi, Junsei Tokuda
We derive constraints on scalar field theories coupled to gravity by using recently developed positivity bounds in the presence of gravity. It is found that a canonically-normalize…
Is the Standard Model in the Swampland? Consistency Requirements from Gravitational Scattering
Katsuki Aoki, Tran Quang Loc, Toshifumi Noumi +1
We study compatibility of the Standard Model of particle physics and General Relativity by means of gravitational positivity bounds, which provide a necessary condition for a low-e…
Spiky strings in de Sitter space
Mitsuhiro Kato, Kanji Nishii, Toshifumi Noumi +2
We study semiclassical spiky strings in de Sitter space and the corresponding Regge trajectories, generalizing the analysis in anti-de Sitter space. In particular we demonstrate th…
Perturbative unitarity in quasi-single field inflation
Suro Kim, Toshifumi Noumi, Keito Takeuchi +1
We study implications of perturbative unitarity for quasi-single field inflation with the inflaton and one massive scalar. Analyzing high energy scattering, we show that non-Gaussi…
Proof of new S-matrix formula from classical solutions in open string field theory (or, Deriving on-shell open string field amplitudes without using Feynman rules, Part II)
Toru Masuda, Hiroaki Matsunaga, Toshifumi Noumi
We study relation between the gauge invariant quantity obtained in [arXiv:1908.09784] and the Feynman diagrams in the dressed gauge in the open cubic string field…
Wavefunctions in dS/CFT revisited: principal series and double-trace deformations
Hiroshi Isono, Hoiki Madison Liu, Toshifumi Noumi
We study wavefunctions of heavy scalars on de Sitter spacetime and their implications to dS/CFT correspondence. In contrast to light fields in the complementary series, heavy field…
invariant Fierz-Pauli massive gravity
Toshifumi Noumi, Kaishu Saito, Jiro Soda +1
We consider an invariant massive deformation of double field theory at the level of free theory. We study Kaluza-Klein reduction on and…
Duality and Supersymmetry Constraints on the Weak Gravity Conjecture
Gregory J. Loges, Toshifumi Noumi, Gary Shiu
Positivity bounds coming from consistency of UV scattering amplitudes are in general insufficient to prove the weak gravity conjecture for theories beyond Einstein-Maxwell. Additio…
Duality and Axionic Weak Gravity
Stefano Andriolo, Tzu-Chen Huang, Toshifumi Noumi +2
The axionic weak gravity conjecture predicts the existence of instantons whose actions are less than their charges in appropriate units. We show that the conjecture is satisfied fo…
Effective Field Theory of Anisotropic Inflation and Beyond
Jinn-Ouk Gong, Toshifumi Noumi, Gary Shiu +3
We develop an effective-field-theory (EFT) framework for inflation with various symmetry breaking pattern. As a prototype, we formulate anisotropic inflation from the perspective o…
Thermodynamics of 4D Dilatonic Black Holes and the Weak Gravity Conjecture
Gregory J. Loges, Toshifumi Noumi, Gary Shiu
Taking a thermodynamic perspective, we study the weak gravity conjecture in the context of 4D Einstein-Maxwell-dilaton theory. We find closed-form expressions for the corrected the…
Momentum space approach to crossing symmetric CFT correlators II: General spacetime dimension
Hiroshi Isono, Toshifumi Noumi, Gary Shiu
Our previous work [1] constructed, in three-dimensional momentum space, a manifestly crossing symmetric basis for scalar conformal four-point functions, based on the factorization…
Effective Lagrangian for Nambu-Goldstone modes in nonequilibrium open systems
Masaru Hongo, Suro Kim, Toshifumi Noumi +1
We develop the effective field theory of diffusive Nambu-Goldstone (NG) modes associated with spontaneous internal symmetry breaking taking place in nonequilibrium open systems. Th…
String Regge trajectory in de Sitter space and implications for inflation
Toshifumi Noumi, Toshiaki Takeuchi, Siyi Zhou
We study the spectrum of semiclassical rotating strings in de Sitter space and its consistency. Even though a naive extrapolation of the linear Regge trajectory on flat space impli…
Heavy Spinning Particles from Signs of Primordial Non-Gaussianities: Beyond the Positivity Bounds
Suro Kim, Toshifumi Noumi, Keito Takeuchi +1
Within the so-called cosmological collider program, imprints of new particles on primordial non-Gaussianities have been studied intensively. In particular, their non-analytic featu…
Momentum space conformal three-point functions of conserved currents and a general spinning operator
Hiroshi Isono, Toshifumi Noumi, Toshiaki Takeuchi
We construct conformal three-point functions in momentum space with a general tensor and conserved currents of spin and . While conformal correlators in momentum space have…