273 citations · 1.4k across the 54 of their papers we have counts for
42 papers · 1 filter
Time evolution of scalar condensate decay
Ayuki Kamada, Kodai Sakurai
A scalar field, which oscillates coherently over the space and decays through production of daughter particles, plays an important role in cosmology. It was recently shown that the…
Generalized Glauber theorem for dark-matter axion and graviton detection
Jakub Bręczewski, Ayuki Kamada, Akira Miyazaki
We revisit the generalized Glauber theorem motivated by recent applications to dark-matter axion searches and graviton production. For Hamiltonian containing up to quadratic terms…
Decay of a scalar condensate in two different approaches
Ayuki Kamada, Kodai Sakurai
Decay of a scalar condensate via interactions with (quasi-)particles is of interest to many fields in physics, including cosmology. In cosmology, the decay of an inflaton condensat…
Revisiting Q-ball Interactions with Matters
Ayuki Kamada, Takumi Kuwahara, Keiichi Watanabe
Q-ball dark matter is one of the candidates for the macroscopic dark matter: Q-ball is a non-topological solitonic configuration, whose stability can be ensured by global charge an…
Composite asymmetric dark matter with a dark photon portal: Multimessenger tests
Saikat Das, Ayuki Kamada, Takumi Kuwahara +2
Composite asymmetric dark matter (ADM) is the framework that naturally explains the coincidence of the baryon density and the dark matter density of the Universe. Through a portal…
Mediator Decay through mixing with Degenerate Spectrum
Ayuki Kamada, Takumi Kuwahara, Shigeki Matsumoto +2
The decay of the mediator particle into standard model (SM) particles plays a significant role in exploring the dark sector scenario. We consider such a decay, taking the dark phot…
Quantum Theory of Dark Matter Scattering
Ayuki Kamada, Takumi Kuwahara, Ami Patel
Dark matter self-scattering is one of key ingredients for small-scale structure of the Universe, while dark matter annihilation is important for the indirect measurements. There is…
Perturbative Unitarity of Strongly Interacting Massive Particle Models
Ayuki Kamada, Shin Kobayashi, Takumi Kuwahara
Dark pion is a promising candidate for the strongly interacting massive particle dark matter. A large pion self-coupling tends to be required for correct relic abundance,…
LHC Lifetime Frontier and Visible Decay Searches in Composite Asymmetric Dark Matter Models
Ayuki Kamada, Takumi Kuwahara
The LHC lifetime frontier will probe dark sector in near future, and the visible decay searches at fixed-target experiments have been exploring dark sector. Composite asymmetric da…
Manifesting hidden dynamics of a sub-component dark matter
Ayuki Kamada, Hee Jung Kim, Jong-Chul Park +1
We emphasize the distinctive cosmological dynamics in multi-component dark matter scenarios and its impact in probing a sub-dominant component of dark matter. We find that the ther…
Maximally self-interacting dark matter: models and predictions
Ayuki Kamada, Hee Jung Kim, Takumi Kuwahara
We study self-interacting dark matter (SIDM) scenarios, where the -wave self-scattering cross section almost saturates the Unitarity bound. Such self-scattering cross sections a…
Strongly-interacting massive particle and dark photon in the era of intensity frontier
Ayuki Kamada, Masaki Yamada, Tsutomu T. Yanagida
A strongly interacting massive particle (SIMP) is an interesting candidate for dark matter (DM) because its self-interaction cross section can be naturally strong enough to address…
Escalating core formation with dark matter self-heating
Ayuki Kamada, Hee Jung Kim
Exothermic scatterings of dark matter (DM) produce DM particles with significant kick velocities inside DM halos. In collaboration with DM self-interaction, the excess kinetic ener…
Lessons from on inflation models: two-loop renormalization of in the scalar QED
Ayuki Kamada, Takumi Kuwahara
A non-minimal coupling has been attracting growing interest particularly in the context of inflation models, though its quantum nature is not clear yet. We study the renormaliz…
Lessons from on inflation models: two-scalar theory and Yukawa theory
Ayuki Kamada, Takumi Kuwahara
We demonstrate two properties of the trace of the energy-momentum tensor in the flat spacetime. One is the decoupling of heavy degrees of freedom; i.e., heavy degrees o…
Unification for the Darkly Charged Dark Matter
Ayuki Kamada, Masaki Yamada, Tsutomu T. Yanagida
We provide a simple UV theory for a Dirac dark matter with a massless Abelian gauge boson. We introduce a single fermion transforming as the representation in the SO(10)$…
Constraining FIMP from the structure formation of the Universe: analytic mapping from
Ayuki Kamada, Keisuke Yanagi
A feebly interacting massive particle (FIMP), contrasting with a weakly interacting massive particle (WIMP), is an intriguing dark matter (DM) candidate. Light (keV-scale) FIMP DM…
Baryon-Dark Matter Coincidence in Mirrored Unification
Masahiro Ibe, Ayuki Kamada, Shin Kobayashi +2
About 80\% of the mass of the present Universe is made up of the unknown (dark matter), while the rest is made up of ordinary matter. It is a very intriguing question why the {\it…
Unification of the Standard Model and Dark Matter Sectors in [SU(5)U(1)]
Ayuki Kamada, Masaki Yamada, Tsutomu T. Yanagida
A simple model of dark matter contains a light Dirac field charged under a hidden U(1) gauge symmetry. When a chiral matter content in a strong dynamics satisfies the t'Hooft anoma…
On Scalaron Decay via the Trace of Energy-Momentum Tensor
Ayuki Kamada
In some inflation scenarios such as inflation, a gravitational scalar degrees of freedom called scalaron is identified as inflaton. Scalaron linearly couples to matter via…
Smallest Halos in Thermal Wino Dark Matter
Shin'ichiro Ando, Ayuki Kamada, Toyokazu Sekiguchi +1
(Mini) split supersymmetry explains the observed Higgs mass and evades stringent constraints, while keeping good features of TeV-scale supersymmetry other than the little hierarchy…
Ultraviolet Completion of a Composite Asymmetric Dark Matter Model with a Dark Photon Portal
Masahiro Ibe, Ayuki Kamada, Shin Kobayashi +2
Composite asymmetric dark matter scenarios naturally explain why the dark matter mass density is comparable with the visible matter mass density. Such scenarios generically require…
Self-interacting dark matter with a vector mediator: kinetic mixing with U(1) gauge boson
Ayuki Kamada, Masaki Yamada, Tsutomu T. Yanagida
A spontaneously broken hidden U(1) gauge symmetry can explain both the dark matter stability and the observed relic abundance. In this framework, the light gauge boson can medi…
Decaying axinolike dark matter: Discriminative solution to small-scale issues
Kyu Jung Bae, Ayuki Kamada, Hee Jung Kim
The latest Lyman- forest data severely constrain the conventional warm dark matter solution to small-scale issues in the cold dark matter paradigm. It has been also reported tha…