9 citations · 31 across the 9 of their papers we have counts for
9 papers
Quantum fluctuation of stress tensor in a higher-derivative scalar field theory around a cosmic string
Nahomi Kan, Masashi Kuniyasu, Kiyoshi Shiraishi
We calculate the vacuum fluctuation of the stress tensor of a higher-derivative theory around a thin cosmic string. To this end, we adopt the method to obtain the stress tensor fro…
Discrete heat kernel, UV modified Green's function, and higher derivative theories
Nahomi Kan, Masashi Kuniyasu, Kiyoshi Shiraishi +1
We perform the UV deformation of the Green's function in free scalar field theory using a discrete heat kernel method. It is found that the simplest UV deformation based on the dis…
Vacuum expectation values in non-trivial background space from three types of UV improved Green's functions
Nahomi Kan, Masashi Kuniyasu, Kiyoshi Shiraishi +1
We evaluate the quantum expectation values in non-simply connected spaces by using UV improved Green's functions proposed by Padmanabhan, Abel, and Siegel. It is found that the res…
Equivalent Hamiltonian approach to quantum cosmology of integrable models
Nahomi Kan, Masashi Kuniyasu, Kiyoshi Shiraishi +1
We propose an approach to quantum cosmology of integrable models. To analyze the models with two dynamical variables, we introduce equivalent Hamiltonians in reduced phase spaces,…
Accelerating cosmologies in an integrable model with noncommutative minisuperspace variables
Nahomi Kan, Masashi Kuniyasu, Kiyoshi Shiraishi +1
We study classical and quantum noncommutative cosmology with a Liouville-type scalar degree of freedom. The noncommutativity is imposed on the minisuperspace variables through a de…
Integrable higher-dimensional cosmology with separable variables in an Einstein-dilaton-antisymmetric field theory
Nahomi Kan, Masashi Kuniyasu, Kiyoshi Shiraishi +1
We consider a -dimensional cosmological model with a dilaton field and two -form field strengths which have nonvanishing fluxes in extra dimensions. Exact solutions for…
Can we identify massless braneworld black holes by observations?
M. Kuniyasu, K. Nanri, N. Sakai +3
For an extension of the previous work on gravitational lensing by massless braneworld black holes, we investigate their microlensing phenomena and shadows and discuss how to distin…
New Solutions of the Dimensional Einstein Gravity Coupled to Maxwell Power type Non Linear Electric field with Dilaton field
Masashi Kuniyasu
New solutions are derived in the gravity which is coupled to type non-linear electric field in Maxwell Power theory with dilaton field. We obtain consistent so…
A New 2+1 Dimensional Einstein Gravity Solution Coupled to Born-Infeld Electromagnetic Theory without Cosmological Constan
Masashi Kuniyasu
A new solution of the Einstein-Born-Infeld theory in 2+1 space-time is derived. A new solution has no horizon there are two singularity. This space-time has two singular points, ho…