40 citations · 278 across the 24 of their papers we have counts for
24 papers
Chromatic number of random graphs: an approach using a recurrence relation
Yayoi Abe, Auna Setoh, Gen Yoneda
The vertex coloring problem to find chromatic numbers is known to be unsolvable in polynomial time. Although various algorithms have been proposed to efficiently compute chromatic…
Stability analysis and improvement of the covariant BSSN formulation against the FLRW spacetime background
Hidetomo Hoshino, Takuya Tsuchiya, Gen Yoneda
In this study, we investigate the numerical stability of the covariant Baumgarte--Shapiro--Shibata--Nakamura (cBSSN) formulation against the Friedmann--Lemaître--Robertson--Walker…
On the stability of covariant BSSN formulation
Ryosuke Urakawa, Takuya Tsuchiya, Gen Yoneda
In this study, we investigate the numerical stability of the covariant BSSN (cBSSN) formulation proposed by Brown. We calculate the constraint amplification factor (CAF), which is…
Stable numerical simulation of Einstein equations in gravitational collapse space--time
Takuya Tsuchiya, Ryosuke Urakawa, Gen Yoneda
We perform simulations in a gravitational collapsing model using the Einstein equations. In this paper, we review the equations for constructing the initial values and the evolutio…
Constraint-Preserving Scheme for Maxwell's Equations
Takuya Tsuchiya, Gen Yoneda
We derive the discretized Maxwell's equations using the discrete variational derivative method (DVDM), calculate the evolution equation of the constraint, and confirm that the equa…
Constructing of constraint preserving scheme for Einstein equations
Takuya Tsuchiya, Gen Yoneda
We propose a new numerical scheme of evolution for the Einstein equations using the discrete variational derivative method (DVDM). We derive the discrete evolution equation of the…