SPACE seminar: Sreemanti Chakraborti - "From Quantum Sensors to Cosmic Constraints: Exploring Ultralight Axion-like Dark Matter"

Tuesday 2 Dec 2025, 12:00 → 13:00 Europe/Rome

Aula 4 (San Marcellino)

Speaker: Dr. Sreemanti Chakraborti (Institute for Particle Physics Phenomenology, Durham University, UK)

Abstract: Axion-like particles (ALPs) remain among the most motivated candidates for ultralight dark matter, where their coherent field behaviour can induce small but measurable shifts in fundamental constants. Starting from gluon and photon couplings at the ultraviolet scale and proceeding through the standard axion effective-field-theory framework, I will discuss how precision quantum sensors—such as atomic clocks, gravitational-wave detectors, resonant microwave cavities, and upcoming platforms like nuclear clocks and atom interferometers—can probe these signatures with exceptional sensitivity, particularly in regions corresponding to large axion decay constants. While linear ALP couplings are restricted by their pseudoscalar nature, quadratic interactions behave effectively as scalar dark matter, motivating distinct experimental strategies. I will present the current and projected reach of these sensing platforms and place them in context with complementary astrophysical and cosmological probes, including black-hole superradiance, Lyman-α, and Big-Bang-nucleosynthesis limits. Finally, I will comment on how the nonlinear behaviour of ultralight fields in dense terrestrial environments may influence sensor responses. Together, these studies highlight the complementarity between quantum-sensing and astroparticle approaches to exploring the light dark matter sector, and the opportunities for cross-disciplinary synergy.

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