14–17 Apr 2025
Portugal
Atlantic/Azores timezone

Contribution List

28 out of 28 displayed
Export to PDF
  1. 14/04/2025, 09:45
  2. Jorge Romão (Instituto Superior Tecnico, Lisbon)
    14/04/2025, 10:00

    We discuss the constraints and phenomenology of the Z2×Z2 three Higgs
    doublet model (3HDM) with two inert scalars, originating two dark matter
    (DM) particles. We elucidate the competing vacua and we submit the model
    to all theoretical, collider and astrophysical constraints. We find
    unexplored regions of parameter space and investigate their experimental
    signatures. The whole mass range...

    Go to contribution page
  3. Prof. Eugene Oks (Auburn University, USA)
    14/04/2025, 10:30

    Dark Hydrogen Atoms as Baryonic Dark Matter
    From the most detailed map of the cosmic microwave background at the end of the recombination
    epoch, the Plank Collaboration deduced the existence of the baryonic dark matter (DM) in the ratio
    1:5 to the non-baryonic DM. So, the baryonic DM does exist. The explanation of a puzzling
    observation by Bowman et al (2018) of the redshifted 21 cm...

    Go to contribution page
  4. Luxi Zheng (University of Tartu)
    14/04/2025, 11:30

    The Lorentz gauge theory of gravity with a spontaneous symmetry breaking field,
    sometimes dubbed ”khronon”, provides a successful description of the ΛCDM model in
    which the dark matter candidate arises as a geometric effect. A chiral formulation of this
    theory has been found to be an extension of General Relativity, and this theory is being
    studied in phenomenological contexts of black...

    Go to contribution page
  5. Titouan Lazeyras (Università degli Studi di Milano Bicocca)
    14/04/2025, 12:00

    The properties of dark matter affect its distribution in the universe. In particular, the mass of dark matter defines a characteristic free streaming length under which structure formation is suppressed. While this length is negligible for standard cold dark matter, it can be of the order of galactic sizes for warm dark matter with mass ~ 1keV, and thus have observational effects. Current...

    Go to contribution page
  6. Francisco Lobo
    14/04/2025, 14:30

    The possibility that dark matter, whose existence is inferred from the study of the galactic rotation curves, and from the mass deficit in galaxy clusters, can be in a form of a Bose-Einstein Condensate, has been recently extensively investigated. In this talk, we consider a detailed analysis of the astrophysical properties of the Bose-Einstein Condensate dark matter halos that could provide...

    Go to contribution page
  7. Nico Benincasa
    14/04/2025, 15:00

    This study explores the parameter space of a minimal extension
    of the Standard Model with a non-abelian SU(2) group, in which the gauge
    bosons are stable and acquire mass through a mechanism of spontaneous
    symmetry breaking involving a new scalar doublet which interacts with
    the Higgs boson through a quartic coupling. The exploration aims to
    assess whether it is possible to obtain a...

    Go to contribution page
  8. Maria Margarida Lima (CAMGST - IST & Okeanos - UAç, Portugal)
    14/04/2025, 16:00

    In this project we will analyse a theory with non-minimal matter–curvature coupling,
    considering non–metricity properties with a Weyl connection. This model has the
    advantage of an extra force term which can mimic dark matter and dark energy, and
    simultaneously follow Weyl’s idea of unifying gravity and electromagnetism. Indeed,
    we can show astrophysical results like Schwarzschild and...

    Go to contribution page
  9. Rui Santos (ISEL and CFTC-UL)
    14/04/2025, 16:30

    I will report on some recent results on simple extensions of the Standard Model with scalar Dark matter candidates.

    Go to contribution page
  10. Nuno Barros e Sá (Universidade dos Açores)
    14/04/2025, 17:00

    — We present a new perturbative method to find the solutions of systems of equations in the neighbourhood
    of known solutions. Given a known solution to a system of equations, the proposed method allows one to find both the
    dimension of the solution space around it and to construct a power series for the set of solutions in its neighbourhood –
    and it does provide as many such answers as...

    Go to contribution page
  11. Prof. Pyungwon Ko (KIAS (Korea Institute for Advanced Study))
    15/04/2025, 09:30

    The SM for particle physics is surprisingly successful. It is based on symmetry principles of various types. I will first recapitulate basic assumptions and key aspects of the SM, emphasizing differences between global vs. local gauge symmetries. Then I will apply similar assumptions and aspects to the DM model buildings.
    I will discuss a few exemplary DM models and demonstrate...

    Go to contribution page
  12. Ramzi Suleiman
    15/04/2025, 10:00

    In the Cold Dark Matter (CDM) paradigm, galaxies form when gas within dark matter (DM) halos cools and collapses toward the centre of the DM potential well, creating a rotating disc structure that triggers star formation. Dark matter candidates span over 90 orders of magnitude in mass, from ultralight bosons to massive black holes. However, despite extensive large-scale underground experiments...

    Go to contribution page
  13. Oleg Lebedev
    15/04/2025, 11:00

    Non-thermal dark matter models suffer from the ever-present gravitational particle production background, which mars predictivity of the framework altogether. I will discuss a class of freeze-in dark matter models with a low reheating temperature that are free of such problems and are directly testable.

    Go to contribution page
  14. Cláudio Gomes (Centro de Física das Universidades do Minho e do Porto, FCUP)
    15/04/2025, 11:30

    We shall review the cosmic generalisation of the virial theorem, known as the Layzer-Irvine equation, also independently derived by Dmitriev and Zeldovich. This equation has been studied in the literature for both dark matter and dark matter-dark energy interaction models, as well as in the context of alternative theories of gravity. We shall discuss some results of the previous scenarios and...

    Go to contribution page
  15. Milada Margarete Mühlleitner
    15/04/2025, 14:00

    We present the C++ program RelExt for Standard Model (SM) extensions that feature a Dark Matter (DM) candidate. The tool allows to efficiently scan the parameter spaces of these models to find parameter combinations that lead to relic density values which are compatible with the measured value within the uncertainty specified by the user. The code computes the relic density for freeze-out...

    Go to contribution page
  16. Igor Kanatchikov (Natl Center of Quantum Information. Gdansk)
    15/04/2025, 14:30

    Precanonical quantum gravity posits a quantum geometry of spacetime characterized by a fluctuating spin connection foam (SCF). This framework naturally yields a characteristic acceleration scale, $a_*=8\pi G \hbar \varkappa$, which is related to the cosmological constant, $\Lambda \sim (8\pi G \hbar \varkappa)^2$ Here, $\varkappa \sim (\Delta m)^3$ represents a parameter inherent to the...

    Go to contribution page
  17. Drona Vatsyayan
    15/04/2025, 15:30

    We consider an extended seesaw model which generates active neutrino masses via the usual type-I seesaw and leads to a large number of massless fermions as well as a sterile neutrino dark matter (DM) candidate in the O(10−100) keV mass range. The dark sector comes into thermal equilibrium with Standard Model neutrinos after neutrino decoupling and before recombination via a U(1) gauge...

    Go to contribution page
  18. Miguel Pinto (Institute of Astrophysics and Space Sciences)
    15/04/2025, 16:00

    Recently, a Modified Gravity Theory named Einstein-scalar-Gauss-Bonnet (EsGB) gravity, a string-inspired theory that admits a coupling between an extra scalar field and the Gauss-Bonnet invariant, has been gaining some attention due to its rich phenomenology. Motivated by its theoretical advancements, we explored the cosmology of the theory in a model-independent manner by using the dynamical...

    Go to contribution page
  19. Josef Pradler (University of Vienna & Austrian Academy of Sciences (AT))
    16/04/2025, 09:30

    Strongly interacting massive particles π have been advocated as prominent dark matter candidates when they regulate their relic abundance through odd-numbered 3π→2π annihilation. We show that successful freeze-out may also be achieved through even-numbered interactions XX→ππ once bound states X among the particles of the low-energy spectrum exist. In addition, X-formation hosts the potential...

    Go to contribution page
  20. Elena Pinetti
    16/04/2025, 10:00

    Axions with a mass around 1 eV can decay into near-infrared photons. Utilising blank-sky observations from the James Webb Space Telescope, I search for a narrow emission line due to decaying dark matter and derive leading constraints on the axion-photon coupling in the eV-scale mass range.

    Go to contribution page
  21. Masoud Ghezelbash (University of saskatchewan)
    16/04/2025, 11:00

    We extend the black hole holography to the case of an asymptotically anti-de Sitter (AdS) rotating charged black holes in f (T) = T + αT2 gravity, where α is a constant. We find that the scalar wave radial equation at the near-horizon region implies the existence of the 2D conformal symmetries. We show that choosing proper central charges for the dual CFT, we produce exactly the macroscopic...

    Go to contribution page
  22. David Dunsky
    16/04/2025, 11:30

    Rapidly Oscillating Massive Particles (ROMPs) arise in quantum systems with non-diagonal interaction Hamiltonians. This misalignment between flavor and mass eigenstates leads to oscillations between flavor states, such as those between electron and muon neutrinos in the Standard Model, or between active and sterile neutrinos in Beyond the Standard Model frameworks to name just a few examples....

    Go to contribution page
  23. 16/04/2025, 15:00

    The Sete Cidades volcano is situated on the extreme western portion of the island of São Miguel occupying an area of approximately 110 square kilometres (42 sq mi) and refers to a polygenetic volcano (Sete Cidades Massif) and caldera.[6] Its subaerial volume, of about 70 cubic kilometres (17 cu mi), has grown at an estimated rate of 0.02–0.03 cubic kilometres (0.0048–0.0072 cu mi) per century,...

    Go to contribution page
  24. Jaime Haro Cases
    17/04/2025, 09:30

    In this talk, I address the gravitational production of dark matter in two distinct scenarios:
    first, when reheating is driven by gravitational particle production, and second, when reheating is dominated by the decay of the inflaton field.
    I establish a relationship between the reheating temperature and the mass of dark matter, and by leveraging the constraints on reheating,
    I...

    Go to contribution page
  25. Rafael Filipe Teixeira Boto (Instituto Superior Técnico)
    17/04/2025, 10:00

    When building dark matter (DM) models, one often imposes conserved discrete symmetries to stabilize DM candidates. The simplest choice is Z2 but models with larger stabilizing groups have also been explored. Can a conserved non-abelian group lead to a viable DM model? Here, we address this question within the three-Higgs-doublet model based on the group Σ(36), in which DM stabilization by a...

    Go to contribution page
  26. Mr Abhishek Chikkaballi (National Center for Nuclear Research, Warsaw)
    17/04/2025, 11:00

    Many dark matter models become unviable when embedded into the framework of asymptotically safe quantum gravity. In this work, we investigate dark matter arising as bound states of fundamental fermions in the strongly-coupled regime of a gauge theory. Modeling the self-interactions of dark baryons via the effective-range approach, we perform a multi-scale analysis in which we combine...

    Go to contribution page
  27. Javeria Makda
    17/04/2025, 11:30

    In this work we derive limits on the WIMP-nucleon scattering cross-section by
    comparing the potential heat flow within the Earth from Dark Matter capture and
    subsequent annihilation to the observational value. This effect has been argued
    previously in the literature to provide a potential link to mass extinction phenomena
    on Earth. However, we focus on whether additional heat-flux from...

    Go to contribution page
  28. Francesco Costa
    17/04/2025, 12:00

    When the Dark Matter (DM) mass is higher than the maximal temperature of the thermal bath, DM can produced via the freeze-in mechanism with coupling as high as O(1). This leads to an observationally attractive scenario compared to the standard freeze-in couplings that are O(10^−10). In fact, it can be probed by direct detection experiments and at LHC.
    We display this mechanism in the scalar...

    Go to contribution page