20th Patras Workshop on Axions, WIMPs and WISPs

Session

Morning - 10

26 Sept 2025, 11:00

76. Looking for ultra-light axions using dwarf galaxies

Andrea Caputo

26/09/2025, 11:00

TBD

5. Ultra-deep astronomical imaging to probe the dark matter properties

Ignacio Trujillo

26/09/2025, 11:20

The large-scale structure of the Universe strongly supports the hypothesis that collisionless cold dark matter is a good description of the nature of dark matter. However, at the scale of galaxies, this simple hypothesis faces several problems that remain unresolved. In particular, the existence of very low-mass galaxies and their internal structure pose a challenge to this simple dark matter...

69. Tunable haloscope at 10 GHz probing up to KSVZ QCD axion models

Giosue' Sardo Infirri (Istituto Nazionale di Fisica Nucleare)

26/09/2025, 11:40

We report the QUAX haloscope improvements for the search of post-inflationary QCD axions at about $10\,$GHz frequency. With respect to previous QUAX results, a wide-tuning system is introduced and proved to work in a quasi-automatic protocol.

The haloscope resonator is a cylindrical copper cavity with a sapphire inner cylinder, which allows for a higher effective volume compared to an empty...

7. The stellar distribution in ultra-faint dwarf galaxies challenges collisionless cold dark matter

Jorge Sanchez Almeida (Instituto de Astrofisica de Canarias)

26/09/2025, 12:00

We present evidence for deviations from the collisionless Cold Dark Matter (CDM) paradigm. In the standard model, dark matter (DM) is collisionless and forms halos with dense central cusps, known as NFW profiles. However, observed galaxies often exhibit flat central cores, typical of systems in thermodynamic equilibrium. While baryonic processes can transform cusps into cores in more massive...

84. SRG/eROSITA and the first uncontaminated view of the diffuse soft X-ray sky

Dr Konrad Dennerl

26/09/2025, 12:20

"From December 2019 to February 2022, SRG/eROSITA has scanned the whole sky at 0.2-8 keV, with
highest sensitivity in the soft (0.2-2.3 keV) X-ray band. Although designed primarily for cosmological studies, the eROSITA mission is also ideally suited for studying our immediate astronomical environment: the discovery of cometary X-ray emission has made us aware that we are observing the sky...

34. A Novel Spiral-Based Tuning Mechanism for Plasma Haloscopes

Junu Jeong (Stockholm University)

26/09/2025, 12:40

The plasma haloscope is a promising variant of cavity haloscope for axion dark matter searches, employing an array of equidistant metallic wires. ALPHA is a global collaboration dedicated to the development and operation of such plasma haloscope experiments. The resonant frequency of these wire-array cavities is primarily determined by the inter-wire spacing, enabling access to higher mass...