5 papers
How Dilatation Invariance Suppresses Loop Corrections to Curvature Perturbations on CMB Scales
Danilo Artigas, Shi Pi, Takahiro Tanaka +1
Departures from standard slow-roll (SR) inflation have attracted increasing interest in recent years. In particular, scenarios that strongly enhance the power spectrum of the curva…
Gravitationally Induced Quantum Decoherence of Macroscopic Objects
Hiroki Takeda, Shogo Tomizuka, Takahiro Tanaka
We formulate the gravitationally induced quantum decoherence of a massive object prepared in a spatial superposition. Starting from linearized gravity coupled to a massive system p…
Locality in effective field theory for inflationary soft modes
Takahiro Tanaka, Yuko Urakawa
The gradient expansion and the separate universe approach provide an effective description of inflationary soft modes after coarse-graining shorter-wavelength degrees of freedom. W…
The Possibility of Formation of Compact Boson Stars via Cosmological Evolution of a Background Scalar Field
Yu Miyauchi, Takahiro Tanaka
Boson stars, hypothetical astrophysical objects bound by the self-gravity of a scalar field, have been widely studied as a type of exotic compact object that is horizonless and pro…
Extended formalism: Nonspatially Flat Separate Universe Approach
Danilo Artigas, Shi Pi, Takahiro Tanaka
The formalism is a powerful approach to compute non-linearly the large-scale evolution of the comoving curvature perturbation . It assumes a set of FLRW patches that evol…