3 papers
astro-ph.CO2026
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…
math.PR2026
Elephant Random Walks on Coverings of Dipole Graphs
Nobuaki Naganuma, Kaito Yura
In the present paper, we introduce and analyze elephant random walks (ERWs) on bipartite periodic lattices arising as coverings of dipole graphs. We focus on lattices whose admissi…
astro-ph.CO2025
Parity-violating scalar trispectrum from helical primordial magnetic fields
Kaito Yura, Shohei Saga, Maresuke Shiraishi +1
Some recent observations of the cosmic microwave background (CMB) anisotropies and the large-scale structure of the Universe imply cosmic parity violation. Among possible parity-vi…