66 citations · 529 across the 24 of their papers we have counts for
14 papers · 1 filter
Apparent Acceleration through Large-scale Inhomogeneities --Post-Friedmannian Effects of Inhomogeneities on the Luminosity Distance--
Masumi Kasai
We re-analyze the observed magnitude-redshift relation of type Ia supernovae (SNe Ia) and examine the possibility that the apparent acceleration of the cosmic expansion is not caus…
Toward a No-Go Theorem for an Accelerating Universe through a Nonlinear Backreaction
Masumi Kasai, Hideki Asada, Toshifumi Futamase
The backreaction of nonlinear inhomogeneities to the cosmic expansion is re-analyzed in the framework of general relativity. Apparent discrepancies regarding the effect of the nonl…
Inversion formula for determining parameters of an astrometric binary
Hideki Asada, Toshio Akasaka, Masumi Kasai
It is believed that some numerical technique must be employed for the determination of the system parameters of a visual binary or a star with a planet because the relevant equatio…
Euclidean Algorithm for a Gravitational Lens in a Polynomial Equation
Hideki Asada, Taketoshi Kasai, Masumi Kasai
The Euclidean algorithm in algebra is applied to a class of gravitational lenses for which the lens equation consists of any set of coupled polynomial equations in the image positi…
Separability of Rotational Effects on a Gravitational Lens
Hideki Asada, Masumi Kasai, Tatsuya Yamamoto
We derive the deflection angle up to due to a Kerr gravitational lens with mass and specific angular momentum . It is known that at the linear order in and …
Algebraic Properties of the Real Quintic Equation for a Binary Gravitational Lens
Hideki Asada, Taketoshi Kasai, Masumi Kasai
It has been recently shown that the lens equation for a binary gravitational lens, which is apparently a coupled system, can be reduced to a real fifth-order (quintic) algebraic eq…