[IPARCOS astro-seminar] October 8th 2025 @16:00 (CEST) - "LOFAR & SKA polarized source catalogues as probes of dark sectors", Fumihiro Naokawa, University of Tokyo

[ENRICA BELLOCCHI]

Fumihiro Naokawa, University of Tokyo

LOFAR & SKA polarized source catalogues as probes of dark sectors

Recent analyses of the Cosmic Microwave Background (CMB) polarization have reported hints of "cosmic birefringence" - a uniform rotation of the polarization angle of CMB photons (e.g. Komatsu 2020). If confirmed, this signal would provide strong evidence for new physics, such as axion-like particles or dark-sectors (e.g. Fujita et al. 2021). However, current CMB measurements still face challenges, including systematic uncertainties and difficulties in probing the redshift evolution of the effect. In this context, the polarization of radio galaxies and the morphology of their jets offer independent and complementary probes of cosmic birefringence (e.g. Carroll et al. 1990). Recent and upcoming large catalogues of such sources by LOFAR or SKA (e.g. O'Sullivan et al. 2023) have the potential to reveal the dark sectors of the universe through cosmic birefringence (Naokawa 2025).

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The talk will take place both in person at Room 13 (Ground floor) of Facultad de CC. Físicas (UCM) and online (Zoom and Youtube live).

The Zoom link will be provided on Wednesday morning.

The IPARCOS astro-seminars on Youtube: click here

Full list of the IPARCOS astro seminars and colloquia: here

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Enrica Bellocchi

Investigadora postdoctoral

Departamento de Física de la Tierra y Astrofísica & Instituto de Física de Partículas y del Cosmos
Facultad Ciencias Físicas

Universidad Complutense de Madrid

Plaza Ciencias, 1, E-28040 Madrid, Spain 

Phone: (+34) 91 394 4587

enri...@ucm.es

[ENRICA BELLOCCHI]

Fumihiro Naokawa, University of Tokyo

LOFAR & SKA polarized source catalogues as probes of dark sectors

Recent analyses of the Cosmic Microwave Background (CMB) polarization have reported hints of "cosmic birefringence" - a uniform rotation of the polarization angle of CMB photons (e.g. Komatsu 2020). If confirmed, this signal would provide strong evidence for new physics, such as axion-like particles or dark-sectors (e.g. Fujita et al. 2021). However, current CMB measurements still face challenges, including systematic uncertainties and difficulties in probing the redshift evolution of the effect. In this context, the polarization of radio galaxies and the morphology of their jets offer independent and complementary probes of cosmic birefringence (e.g. Carroll et al. 1990). Recent and upcoming large catalogues of such sources by LOFAR or SKA (e.g. O'Sullivan et al. 2023) have the potential to reveal the dark sectors of the universe through cosmic birefringence (Naokawa 2025).

---

The talk will take place both in person at Room 13 (Ground floor) of Facultad de CC. Físicas (UCM) and online (Zoom and Youtube live).

The link to join the zoom is the following: https://rediris.zoom.us/j/92410435358

The IPARCOS astro-seminars on Youtube: click here

Full list of the IPARCOS astro seminars and colloquia: here