KEK Cosmo 2025

Session

Session II

4 Mar 2026, 13:00

Conveners

Session II

• Pankaj Saha

12. Frontiers of CMB measurements and cosmological tests of Bell inequality

Yuji Chinone

04/03/2026, 13:00

13. Towards the prediction of primordial- black-hole clusters

Danilo Artigas

04/03/2026, 14:00

Primordial black holes (PBHs) are a major candidate for dark matter, expected to form from the collapse of large density fluctuations generated during inflation. Their abundance is highly sensitive to non-linear effects, some of which can be described through the δN formalism. This approach models the universe as a set of locally homogeneous patches evolving independently throughout inflation....

14. Parity-violating scalar trispectrum from helical primordial magnetic fields

Yura Kaito

04/03/2026, 14:20

Observational evidence for cosmic magnetic fields has been accumulated over a wide range of scales, from galaxies and galaxy clusters to cosmic voids, yet their origin remains unsettled. In particular, magnetic fields in voids are difficult to account for solely by astrophysical mechanisms associated with structure formation, making primordial magnetic fields (PMFs) generated in the early...

15. Phenomenological and Gravitational Properties of a Monopole-Domain Wall System

Yu Komiya

04/03/2026, 14:40

We consider an exotic object that may be attained in cosmology models permitting the existence of two interacting defects: the magnetical monopole and an axion domain wall. The system is subject to the Witten effect, which gives rise to unique electromagnetic properties. A stable, gravitating solution of the system is formulated; we discuss its relations to the study of other compact objects,...