222 citations · 441 across the 10 of their papers we have counts for
10 papers
Suppressed cosmic growth in coupled vector-tensor theories
Antonio De Felice, Shintaro Nakamura, Shinji Tsujikawa
We study a coupled dark energy scenario in which a massive vector field with broken gauge symmetry interacts with the four-velocity of cold dark matter (CDM) t…
Quadrupolar Susceptibility and Magnetic Phase Diagram of PrNiCd with Non-Kramers Doublet Ground State
Tatsuya Yanagisawa, Hiroyuki Hidaka, Hiroshi Amitsuka +8
In this study, ultrasonic measurements were performed on a single crystal of cubic PrNiCd, down to a temperature of 0.02 K, to investigate the crystalline electric field…
Coupled vector dark energy
Shintaro Nakamura, Ryotaro Kase, Shinji Tsujikawa
We provide a general framework for studying the evolution of background and cosmological perturbations in the presence of a vector field coupled to cold dark matter (CDM). We…
Helical Ordering of Spin Trimers in a Distorted Kagome Lattice of GdRuAl Studied by Resonant X-ray Diffraction
Takeshi Matsumura, Yusaku Ozono, Shintaro Nakamura +2
Successive magnetic phase transitions at =17.5 K and =18.5 K in GdRuAl, with a distorted kagome lattice of Gd ions, is studied using resonant X-ray diffrac…
Constraints on massive vector dark energy models from integrated Sachs-Wolfe-galaxy cross-correlations
Shintaro Nakamura, Antonio De Felice, Ryotaro Kase +1
The gravitational-wave event GW170817, together with the electromagnetic counterpart, shows that the speed of tensor perturbations on the cosmological background is very clos…
Suppression of matter couplings with a vector field in generalized Proca theories
Shintaro Nakamura, Ryotaro Kase, Shinji Tsujikawa
We derive the profile of a vector field coupled to matter on a static and spherically symmetric background in the context of generalized Proca theories. The cubic Galileon self-int…