10 papers
Primordial tensor mode from the neutrino sector
Shohei Saga, Shuichiro Yokoyama
We show that a regular solution for primordial tensor fluctuations can arise from the higher-order multipoles of the collisionless neutrino distribution after neutrino decoupling.…
Shapes and orientations of massive halos in the statistically anisotropic universe
Shogo Masaki, Yurino Mizuguchi, Shohei Saga +1
We investigate how statistical anisotropy (SA) in matter distributions affects the distributions of shapes and orientations of cluster-sized halos, using cosmological -body simu…
Revisiting constraints on primordial vector modes and implications for sourced magnetic fields and observed power spectrum
Kaito Yura, Shohei Saga, Shuichiro Yokoyama +1
We revisit regular primordial vector modes sustained by the anisotropic stress of free-streaming neutrinos. We consider two classes of neutrino-sector initial conditions, the neutr…
PySCo-EFT and ECOSMOG-EFT: a tandem of N-body simulation codes for the Effective Field Theory of Dark Energy
Himanish Ganjoo, Yann Rasera, Emilio Bellini +18
Modified gravity theories constitute viable alternatives to the standard cosmological model for explaining the observed late-time accelerated expansion of the Universe. The Effecti…
On the shape of pancakes: catastrophe theory and Gaussian statistics in 2D
Abineet Parichha, Stephane Colombi, Shohei Saga +1
Cold dark matter (CDM) can be thought of as a 2D (or 3D) sheet of particles in 4D (or 6D) phase-space due to its negligible velocity dispersion. The large-scale structure, also cal…
Post-collapse Lagrangian perturbation theory in three dimensions
Shohei Saga, Stéphane Colombi, Atsushi Taruya +2
The gravitational collapse of collisionless matter leads to shell-crossing singularities that challenge the applicability of standard perturbation theory. Here, we present the firs…