A5032687942- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Quantum Chromodynamics and Particle Interactions
- Quantum Electrodynamics and Casimir Effect
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Galaxies: Formation, Evolution, Phenomena
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2023-2025
Scuola Internazionale Superiore di Studi Avanzati
2023-2025
University of Trieste
2024
Institute for Fundamental Physics of the Universe
2023-2024
Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing an ensemble galactic millisecond radio pulsars. With second data release European Array, we focus on most robust scenario, in which interacts only gravitationally with ordinary baryonic matter. Our results show that masses 10^{-24.0} eV≲m≲10^{-23.3} eV cannot constitute 100% measured local density, but can have at density ρ≲0.3 GeV/cm^{3}.
Abstract A coherently oscillating ultra-light axion can behave as dark matter. In particular, its pressure perturbations source an scalar metric perturbation, with a characteristic oscillation frequency which is twice the Compton frequency. candidate in mass range 10 (-24,-21) eV provide signal tested by current and future Pulsar Timing Array (PTA) programs. Involving highly nonlinear environment, such analysis demands relativistic treatment. Here, we rigorous derivation of effect assuming...
Millisecond pulsars are extremely precise celestial clocks: as they rotate, the beamed radio waves emitted along axis of their magnetic field can be detected with telescopes, which allows for tracking subtle changes in pulsars' rotation periods. A possible effect on period a pulsar is given by potential coupling to dark matter, cases where it modeled an "ultralight" scalar field. In this paper, we consider universal conformal matter gravity, turn mediates effective between and matter. If...
Millisecond pulsars are extremely stable natural timekeepers. Pulsar Timing Array experiments, tracking subtle changes in the pulsars' rotation periods, can shed light on presence of ultralight particles our Galaxy. In this conference paper, we start by reviewing most conservative scenario, which interact only gravitationally. setting, show that Arrays able to constrain fields up a few tenths observed dark matter abundance. Then, consider conformally coupled candidates, demonstrating...
In the presence of a magnetic field, axions can convert into photons and vice versa. The phenomenology conversion is captured by system two coupled Klein-Gordon equations, which, assuming that axion relativistic, usually recast pair first-order Schrödinger-like equations. such limit, focusing on constant field plasma frequency, equations admit an exact analytic solution. relativistic limit significantly simplifies calculations and, therefore, it widely used in phenomenological applications....
A pseudo Nambu-Goldstone boson (PNGB) coupled to a confining gauge group via an anomalous term is characterised, during the phase transition, by temperature dependent mass $m^2(T) \propto T^{-n}$. For $n>2$, non-relativistic population of such particles dominating cosmological energy density would act as dark (DE), accelerating expansion. We study possibility that PNGB $\varphi_b$ hidden presently undergoing confinement could realise this scenario. To obtain observed amount DE, number must...
A bstract local flavour symmetry acting on the quarks of Standard Model can automatically give rise to an accidental global U(1) which remains preserved from sources explicit breaking up a large operator dimension, while it gets spontaneously broken together with symmetry. Such non-fundamental symmetries are often endowed mixed QCD anomaly, so that strong CP problem is solved via axion mechanism. We illustrate general features required realise this scenario, and we discuss simple...
In the presence of a magnetic field, axions can convert into photons and viceversa. The phenomenology conversion is captured by system two coupled Klein-Gordon equations, which, assuming that axion relativistic, usually recast pair first order Schr\"odinger-like equations. such limit, focusing on constant field plasma frequency, equations admit an exact analytic solution. relativistic limit significantly simplifies calculations; therefore, it widely used in phenomenological applications....
A coherently oscillating ultra-light axion can behave as dark matter. In particular, its pressure perturbations source an scalar metric perturbation, with a characteristic oscillation frequency which is twice the Compton frequency. candidate in mass range $10^{(-24,-21)}{\rm eV}$ provide signal tested by current and future Pulsar Timing Array (PTA) programs. Involving highly nonlinear environment, such analysis demands relativistic treatment. Here, we rigorous derivation of effect assuming...
A local flavour symmetry acting on the quarks of Standard Model can automatically give rise to an accidental global $U(1)$ which remains preserved from sources explicit breaking up a large operator dimension, while it gets spontaneously broken together with symmetry. Such non-fundamental symmetries are often endowed mixed QCD anomaly, so that strong CP problem is solved via axion mechanism. We illustrate general features required realise this scenario, and we discuss simple construction...