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Jaime Hoefken Zinkposter
We explore the interactions of dark fermions with the SM that could explain ANITA-IV events through a DIS with nucleons and a decay of a massive dark fermion produced from the interaction. We show the best fit regions to the results such that the model also fits IceCube non-observation.
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Michelle Gurevich (King's College London)poster
We present a special property of natural polynomials related to the overtone label of quasi-normal modes for Schwarzschild black holes. The natural polynomials for the radial Teukolsky equation have been the subject of recent work involving quasinormal modes of Kerr black holes. These polynomials, which can be constructed using Gram-Schmidt orthogonalization, are a basis for the ringdown...
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Bruno Bucciotti (Scuola Normale Superiore di Pisa)poster
We study the quadratic quasi-normal modes of a Schwarzschild black hole, i.e. those perturbations that originate from the coupling of two (linear) quasi-normal modes.
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Assuming the amplitude of the two linear modes is known, we compute the amplitude of the resulting quadratic mode for a wide range of possible angular momenta. Finally, we reconstruct the waveform in radiation gauge. -
Mr Gramos Qerimi (Technical University of Munich (TUM))poster
For a quantitative investigation on the time evolution of heavy thermal dark matter at and after thermal freeze-out, near-threshold processes need to be taken into account which have a large impact on the observed dark matter relic abundance. We study the recoil effect of heavy dark matter pairs in a thermal bath and compute the thermal rates of dark matter fermion-antifermion pairs in the...
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João Pedro Pino Gonçalves (University of Aveiro)poster
Faced with the lack of observational evidence supporting the existence of new physics at the electroweak scale, alongside overwhelming experimental evidence that hints at the need for the exploration of new phenomena, such as neutrino masses/mixing or dark matter, new approaches to beyond the Standard Model (SM) phenomenology become imperative. Gravitational waves stemming from first-order...
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Stefan Ledererposter
My talk will show how the presence of highly excited bound states changes the common assumption of Freeze-Out taking place at $T\approx M/25$. Instead of a decoupling at finite-time, particle densities deplete continuously until additional physical effects occur, e.g. phase transitions or lifetime constraints. We have applied our framework to a t-channel mediator model yielding...
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Vinícius Oliveira (Universidade de Aveiro)poster
Weakly interacting massive particles (WIMPs) are by far the most extensively studied class of CDM as the correct dark matter abundance is easily reproduced with cross sections around the weak scale. They have been extensively searched for by many experiments (direct and indirect detection, and colliders) with no success. The null results reported thus far motivate us to explore alternative...
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Álvaro Parra-López (IPARCOS-UCM (Complutense University of Madrid))poster
Gravitational particle production of spectator fields due to the expansion universe during the inflationary and reheating phases of the early universe is of particular interest in the context of dark matter, since it allows to constrain the properties of the dark candidate
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by comparing the density of particles produced with the observed dark matter abundance. In such processes, tachyonic... -
Dr Ahmed Ayad (Bielefeld University)poster
Axions and axion-like particles (ALPs) have gained attention as potential dark matter candidates, leading to extensive research into their detection and characterization. Energy density fluctuations in the ALP field can result in the formation of axion miniclusters (AMC), gravitationally bound configurations with implications for dark matter structure. While widely accepted in the...
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Boris Betancourt Kamenetskaia (Technical University of Munich)poster
A strongly self-interacting component of dark matter can lead to formation of compact objects. These objects (dark stars) can in principle be detected by emission of gravitational waves from coalescence with black holes or other neutron stars or via gravitational lensing. However, in the case where dark matter admits annihilations, these compact dark matter made objects can have significant...
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Jessie de Kruijf (University of Padova)poster
We investigate how the primordial power spectrum on small scales could be constrained using 21cm line intensity mapping in the dark ages. The focus is on models that imprint an increase of the matter spectrum at large angular multipoles.
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We study a few specific models, including early matter domination, primordial black holes and vector dark matter, and then parameterize small scale features... -
Petr Beneš (Czech Technical University in Prague (CZ))poster
We discuss a class of effective extensions of the SU(2) Georgi–Glashow model and discuss its Bogomol’nyi–Prasad–Sommerfield (BPS) limit. We identify a specific subclass of these models that admit analytical solutions of the monopole type. We present some concrete examples and find that the resulting monopoles tend to have their energy concentrated not in their center, but rather in a spherical...
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Oindrila Ghosh (Stockholm University & the Oskar Klein Centre)poster
Shock waves driven by merger events can continuously source self-generated magnetic fields at the periphery of galaxy clusters. Diffuse non-thermal emission and polarization measurements from radio relics indicate a magnetisation of the intracluster medium due to merger shocks in addition to particle acceleration at the shock site. I will outline the growth and saturation of such magnetic...
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Nastassia Grimmposter
To test the vast number of modified gravity models, a systematic and comprehensive approach is necessary when analysing the data from cosmological surveys. The novel observable \hat{J}, capturing the evolution of the combined gravitational potential Ψ + Φ, provides a powerful and model-independent test of gravity. Recently, we have performed the first measurement of this observable from Dark...
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Anna Kormuposter
In the minimal Standard Model (SM) the Electroweak Phase Transition is a crossover, but in many beyond the SM theories the possibility for a first order transition has sustained interest. Strong first order phase transitions could produce gravitational waves that might be detectable by the Laser Interferometer Space Antenna (LISA). Improving the accuracy of predictions of the nucleation rate...
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Martina Cataldi (University of Hamburg)poster
We propose a novel non-thermal realisation for leptogenesis that relies on the out-of-equilibrium decay of an axion-like particle (ALP) into right-handed Majorana neutrinos (RHN) in the Early Universe, and that it opens the parameter space of successful leptogenesis down to TeV-scale RHNs, with values of $f_a > 10^{11}$ GeV and $m_a > 10^{4}$ GeV for the ALP decay constant and mass.
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We also... -
Dr Yu Hamada (DESY)poster
It is well known that spontaneous breaking of discrete symmetries produce topological objects called domain walls, which must decay in order not to dominate the energy density of the universe. One of the possible decay scenarios is nucleating holes bounded by cosmic strings on the walls. Once they are nucleated, the holes expand faster and faster by eating the energy of the domain walls and...
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Piotr Toczek (University of Warsaw)poster
Slow first-order phase transitions generate large inhomogeneities that can lead to the formation of primordial black holes (PBHs). We show that the gravitational wave (GW) spectrum then consists of a primary component sourced by bubble collisions and a secondary one induced by large perturbations. The latter gives the dominant peak if $\beta/H_0 < 10$, impacting, in particular, the...
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Mateusz Zych (University of Warsaw)poster
Terminal velocity reached by bubble walls in first-order phase transitions is an important parameter determining both primordial gravitational wave spectrum and the production of baryon asymmetry in models of electroweak baryogenesis. We developed a numerical code to study the real-time evolution of expanding bubbles and investigate how their walls reach stationary states. Our results agree...
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Ander Urio (University of the Basque Country)poster
In this talk, I will address the issue of the strong backreaction regime in the abelian axion inflation scenario, extending results from 2303.17436 and ongoing work. I will do a revision of the mild and strong backreaction regimes, during and at the end of inflation, and also show how they can be distinguished in terms of dynamics and lengthening of the inflationary period, as well as, the...
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Marco Finetti (Aveiro University)poster
The electroweak phase transition is a promising explanation for the origin of baryon asymmetry in the universe, a core problem in cosmology and particle physics.
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An extension of the Standard Model is necessary to generate a strong first-order phase transition. Besides representing a target for several future-generation colliders, such Beyond the Standard Model (BSM) theories can generate -... -
Wanda Isnard (IP2I Lyon)poster
We investigate the possibility that inflation originates from a composite field theory, in terms of an effective chiral Lagrangian involving a dilaton and pions. It is possible to find a successful hybrid inflation occurring via the dilaton as the inflaton and the pions as waterfall fields. Compositeness consistency strongly constrain the model such as the composite scale and the inflation...
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Jack Franklinposter
We investigate IceCube's ability to constrain the neutrino relic abundance using events from the recently identified neutrino source NGC1068. Since these neutrinos have large energies $\gtrsim$ 1 TeV and have propagated through large distances, they make a great probe for overabundances of the cosmic neutrino background.
The propagation of neutrinos from NGC1068 was simulated by solving a...
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Sveva Castello (University of Geneva)poster
Combining measurements of the growth rate of cosmic structures with gravitational lensing is considered as the optimal way to test for deviations from General Relativity on cosmological scales. In my talk, I will demonstrate that this standard method suffers from an important limitation, since models of dark matter with additional interactions can lead to exactly the same signatures as...
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Mr Maciej Kierklaposter
We analyze the role of higher-order thermal corrections for supercooled phase transition, and to what extent they can be computed using dimensionally reduced effective field theory (3D EFT). This framework requires high-temperature (HT) expansion to be valid, which seems challenging due to the presence of supercooling. We show how to reliably use the HT expansion in dimensionally reduced...
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Virgile Dandoy (ULB)poster
High-Frequency Gravitational Waves (HFGWs) constitute a unique window on the early Universe as well as exotic astrophysical objects. If the current gravitational wave experiments are more dedicated to the low frequency regime, the graviton conversion into photons in a strong magnetic field constitutes a powerful tool to probe HFGWs. In this paper, we show that neutron stars, due to their...
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Ansh Bhatnagar (IPPP, Durham University)poster
In standard leptogenesis models, the baryon asymmetry is initially produced as a lepton asymmetry via the out of equilibrium decays of the lightest right handed neutrino (RHN).
There are however constraints on the RHN mass that are in tension; the naturalness constraint on the Higgs mass from RHN loop corrections, i.e. the Vissani bound, puts a limit on the RHN mass which is lower than is...
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Daniel Schmitt (Goethe University, Frankfurt)poster
Different thermal resummation techniques impact the gravitational wave (GW) spectra from cosmological first-order phase transitions predicted in a given particle physics model. To investigate this effect, we perform large-scale parameter scans of the electroweak phase transition (EWPT) in the dynamical real-singlet extension of the Standard Model (SM) using three different perturbative...
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Pier Giuseppe Catinari (Sapienza)poster
We apply the criterion of finite naturalness to the limiting case of a generic heavy sector decoupled from the standard model. The sole and inevitable exception is represented by gravitational interactions. We demonstrate how gravity can couple the Higgs to the heavy scale well before the three-loop diagrams mediated by the top quark discussed in previous literature. As an application, we...
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Károly Seller (ELTE Eötvös Loránd University)poster
In this contribution we investigate the viability of leptogenesis in the superweak extension of the standard model. We focus on the parameter space of the model with relatively light sterile neutrinos with masses comparable to the electroweak scale and a new singlet scalar that is heavier than the Higgs boson. We present a comprehensible analysis of leptogenesis within the model with...
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Daniele Perri (SISSA Trieste, Trieste)poster
Magnetic monopoles are intriguing hypothetical particles and inevitable predictions of Theories of Grand Unification. They are produced during phase transitions in the early universe, but mechanisms like the Schwinger effect in strong magnetic fields could also contribute to the monopole number density. I will show how from the detection of intergalactic magnetic fields we can infer additional...
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Alejandro Perez Rodriguez (Universidad Autonoma de Madrid)poster
The non-Gaussian tail of the PDF of primordial scalar perturbations is a key element to determine the abundance of primordial black holes. These primordial non-Gaussianities arise, at least partly, from the non-linear, super-horizon dynamics of inflationary perturbations. Such non-linearities have been computed by combining classical non-linear techniques (the $\delta N$ formalism) with the...
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Jesus Gambin Egea (Instituto de Fisica Teorica, UAM - CSIC)poster
A possible way to generate primordial black holes as candidates for the entirety of dark matter is a large power spectrum of inflationary curvature fluctuations. Recently, questions have been raised regarding the validity of perturbation theory in this context. We compute the one-loop power spectrum in ultra-slow roll inflation, including all relevant interactions for such analysis, along with...
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Devanshu Sharmaposter
Distortions of $\mu$-type in the frequency spectrum of CMB photons are bounded by FIRAS observations. Since peaks in the primordial scalar power spectrum at small scales can enhance them, FIRAS data can be used to set limits on the Primordial Black Hole (PBH) abundance. However, such peaks usually come together with some non-Gaussian statistics in the primordial curvature spectrum which is...
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Simona Procacci (University of Geneva (CH))poster
We consider a model, where a single inflaton interacts as an axion with Yang-Mills gauge bosons. As these rapidly thermalize, the friction felt by the inflaton field is increased, leading to a self-amplifying process. The corresponding gravitational wave spectrum is enhanced by thermal contributions at large confinement scales of the Yang-Mills sector, which heats up to high temperatures, yet...
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Jonas Frerickposter
I will point out the possibility to perform a parametrically improved search for gauged baryon ($B$) and baryon minus lepton ($B-L$) Dark Photon Dark Matter (DPDM) using auxiliary channel data from LISA Pathfinder. In particular I will show how to use the measurement of the differential movement between the test masses (TMs) and the space craft (SC) which is nearly as sensitive as the tracking...
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Dr Oleksandr Sobol (University of Münster)poster
Different models of inflationary magnetogenesis have been receiving a lot of attention in the literature for the last two decades providing a possible explanation for the large-scale magnetic fields in voids, seeds for the astrophysical magnetic fields and having relation to baryogenesis, dark matter production, cosmological Schwinger effect etc. However, the presence of gauge fields during...
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Chiara Cecchini (University of Trento, TIFPA-INFN)poster
Fundamental scale invariance has been proposed as a new theoretical principle beyond renormalizability. Besides its highly predictive power, a scale-invariant formulation of gravity could provide a natural explanation for the long-standing hierarchy problem and interesting applications in cosmology.
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We present a globally scale-invariant model of quadratic gravity and study its solutions in a... -
Matthias Koschnitzke (University of Hamburg/DESY)poster
It is well known that clouds of ultralight particles surrounding black holes produced by the superradiant instability can experience Landau-Zehner transitions if the black hole is part of a binary system.
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We study the effect of orbital eccentricity, backreaction of the cloud onto it and observational possibilities with future gravitational-wave detectors like the Laser Interferometer Space... -
Taylor Gray (Chalmers University of Technology)poster
Sub-GeV dark matter (DM) has been gaining significant interest in recent years, since it can account for the thermal relic abundance while evading nuclear recoil direct detection constraints. Such light DM must carry a larger energy to be probed, either directly or through missing energy/momentum, making beam dump and fixed target experiments ideal for this mass range. Here, we extend the...
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Jordan Koechler (LPTHE - Sorbonne Université (France))poster
We present updated constraints on 'light' Dark Matter (DM) particles with masses between 1 MeV and 5 GeV. In this range, we can expect DM-produced pairs to upscatter low-energy ambient photons in the Milky Way via the Inverse Compton process, and produce a flux of X-rays that can be probed by a range of space observatories. Using diffuse X-ray data from XMM-Newton and realistic cosmic-ray...
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Asmaa Mazounposter
We forecast the sensitivity of ongoing and future galaxy cluster abundance measurements to detect deviations from the cold dark matter (CDM) paradigm. Concretely, we consider a class of dark sector models that feature an interaction between dark matter and a dark radiation species (IDM-DR). This setup can be naturally realized by a non-Abelian gauge symmetry and has the potential to explain...
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Rasmi Enrique Hajjar Muñoz (IFIC (CSIC-UV))poster
One long-standing tension in the determination of neutrino parameters is the mismatched value of the solar mass square difference, $\Delta m^2_{21}$, measured by different experiments: the reactor antineutrino experiment KamLAND finds a best fit larger than the one obtained with solar neutrino data. Even if the current tension is mild ($\sim 1.5\sigma$), it is timely to explore if independent...
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Valentin Weberposter
Heavy neutrinos with masses in the MeV range could in principle simultaneously explain the light neutrino masses via the seesaw mechanism and the origin of baryonic matter in the universe through leptogenesis. Their properties are severely constrained by cosmological considerations, in particular primordial nucleosynthesis. Since these constraints rely on assumptions about the cosmic history,...
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Francesca Scarcella (Laboratoire Univers et Particules de Montpellier (LUPM))poster
The abundance of primordial black holes is constrained by observations of the Cosmic Microwave Background (CMB): these compact objects would accrete matter and emit high-energy photons, altering the statistical properties of the CMB. The presence of dense dark matter mini-halos around the PBHs has been used to further tighten the bounds, as these would boost the accretion rates. In this...
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