activity
20242026
collaborators

8 papers

hep-ph2026

The COSMIC WISPers White Paper: The physics case for Weakly Interacting Slim Particles

Ariel Arza, Deniz Aybas, Shyam Balaji +124

Axions and other very weakly interacting slim particles (WISPs), with masses below 1 GeV, arise naturally in many extensions of the Standard Model of particle physics. In particula…

astro-ph.CO2025

Planck Constraints on Axion-Like Particles through Isotropic Cosmic Birefringence

Toshiya Namikawa, Kai Murai, Fumihiro Naokawa

We present constraints on isotropic cosmic birefringence induced by axion-like particles (ALPs), derived from the analysis of cosmic microwave background (CMB) polarization measure…

astro-ph.CO2025

Resolving the negative effective neutrino mass parameter with cosmic birefringence

Toshiya Namikawa

The recent measurement of baryonic acoustic oscillations by the Dark Energy Spectroscopic Instrument reveals a mild tension with observations of the cosmic microwave background (CM…

astro-ph.CO2025

Tomographic constraint on anisotropic cosmic birefringence

Toshiya Namikawa

We constrain anisotropic cosmic birefringence generated at reionization using Planck PR4 polarization data for the first time. Several recent analyses of WMAP and Planck polarizati…

astro-ph.CO2025

Exact CMB B-mode power spectrum from anisotropic cosmic birefringence

Toshiya Namikawa

We calculate the cosmic microwave background (CMB) -mode power spectrum resulting from anisotropic cosmic birefringence, without relying on the thin approximation of the last sc…

astro-ph.CO2024

Systematic effects on lensing reconstruction from a patchwork of CMB polarization maps

Ryo Nagata, Toshiya Namikawa

We investigate the tolerance for systematic errors in lensing analysis applied to a patchwork map of Cosmic Microwave Background polarization. We focus on the properties of the ind…