Bounds on Dark Matter decay from 21 cm line

The observation of the cosmic 21-cm spectrum can serve as a probe for Dark Matter properties. We point out that the knowledge of the signal amplitude at a given redshift allows one to put conservative bounds on the DM decay rate which are independent of astrophysical parameters. These limits are valid for the vast majority of DM models, those without extra IGM cooling or additional background radiation. Using the experimental results reported by the EDGES collaboration, we derive bounds that are stronger than the ones derived from other CMB observations and competitive with the ones from indirect detection.Comment: 9 pages, 2 figures. v3: Improved discussion of the assumptions, matching to the published version. Bounds for different decay channels included. References adde

Gluequark Dark Matter

We introduce the gluequark Dark Matter candidate, an accidentally stable bound state made of adjoint fermions and gluons from a new confining gauge force. Such scenario displays an unusual cosmological history where perturbative freeze-out is followed by a non-perturbative re-annihilation period with possible entropy injection. When the gluequark has electroweak quantum numbers, the critical density is obtained for masses as large as PeV. Independently of its mass, the size of the gluequark is determined by the confinement scale of the theory, leading at low energies to annihilation rates and elastic cross sections which are large for particle physics standards and potentially observable in indirect detection experiments.Comment: 39 pages, 7 figures. v2: improved discussion of theoretical uncertainties, matching to the published version. References added and typos fixe

Fermions at finite density in the path integral approach

We study relativistic fermionic systems in $3+1$ spacetime dimensions at finite chemical potential and zero temperature, from a path-integral point of view. We show how to properly account for the $i\varepsilon$ term that projects on the finite density ground state, and compute the path integral analytically for free fermions in homogeneous external backgrounds, using complex analysis techniques. As an application, we show that the ${\rm U}(1)$ symmetry is always linearly realized for free fermions at finite charge density, differently from scalars. We study various aspects of finite density QED in a homogeneous magnetic background. We compute the free energy density, non-perturbatively in the electromagnetic coupling and the external magnetic field, obtaining the finite density generalization of classic results of Euler--Heisenberg and Schwinger. We also obtain analytically the magnetic susceptibility of a relativistic Fermi gas at finite density, reproducing the de Haas--van Alphen effect. Finally, we consider a (generalized) Gross--Neveu model for $N$ interacting fermions at finite density. We compute its non-perturbative effective potential in the large-$N$ limit, and discuss the fate of the ${\rm U}(1)$ vector and $\mathbb{Z}_2^A$ axial symmetries.Comment: 34 pages, 6 figures. v2: one reference added, matches published versio

Study the effect of beam energy spread and detector resolution on the search for Higgs boson decays to invisible particles at a future e+^+e−^- circular collider

We study the expected sensitivity to measure the branching ratio of Higgs boson decays to invisible particles at a future circular \epem collider (FCC-ee) in the process $e^+e^-\to HZ$ with $Z\to \ell^+\ell^-$ ($\ell=e$ or $\mu$) using an integrated luminosity of 3.5 ab$^{-1}$ at a center-of-mass energy $\sqrt{s}=240$ GeV. The impact of the energy spread of the FCC-ee beam and of the resolution in the reconstruction of the leptons is discussed. %Two different detector concepts are considered: a detector corresponding to the CMS reconstruction performances and the expected design of the ILC detector. The minimum branching ratio for a $5\sigma$ observation after 3.5ab$^{-1}$ of data taking is $1.7\pm 0.1\%(stat+syst)$. The branching ratio exclusion limit at 95\% CL is $0.63 \pm 0.22\%((stat+syst))$.Comment: 17 pages, submitted to EPJ

Vi(E)va LLM! A Conceptual Stack for Evaluating and Interpreting Generative AI-based Visualizations

The automatic generation of visualizations is an old task that, through the years, has shown more and more interest from the research and practitioner communities. Recently, large language models (LLM) have become an interesting option for supporting generative tasks related to visualization, demonstrating initial promising results. At the same time, several pitfalls, like the multiple ways of instructing an LLM to generate the desired result, the different perspectives leading the generation (code-based, image-based, grammar-based), and the presence of hallucinations even for the visualization generation task, make their usage less affordable than expected. Following similar initiatives for benchmarking LLMs, this paper copes with the problem of modeling the evaluation of a generated visualization through an LLM. We propose a theoretical evaluation stack, EvaLLM, that decomposes the evaluation effort in its atomic components, characterizes their nature, and provides an overview of how to implement and interpret them. We also designed and implemented an evaluation platform that provides a benchmarking resource for the visualization generation task. The platform supports automatic and manual scoring conducted by multiple assessors to support a fine-grained and semantic evaluation based on the EvaLLM stack. Two case studies on GPT3.5-turbo with Code Interpreter and Llama2-70-b models show the benefits of EvaLLM and illustrate interesting results on the current state-of-the-art LLM-generated visualizations

Changes in total choline concentration in the breast of healthy fertile young women in relation to menstrual cycle or use of oral contraceptives: a 3-T 1H-MRS study

BACKGROUND: To evaluate changes in total choline (tCho) absolute concentration ([tCho]) in the breast of healthy fertile women in relation to menstrual cycle (MC) or use of oral contraceptives (OC). METHODS: After institutional review board approval, we prospectively evaluated 40 healthy fertile volunteers: 20 with physiological MC, aged 28 ± 3 years (mean ± standard deviation; nOC group); 20 using OC, aged 26 ± 3 years (OC group). Hormonal assays and water-suppressed single-voxel 3-T proton magnetic resonance spectroscopy (1H-MRS) were performed on MC days 7, 14, and 21 in the nOC group and only on MC day 14 in the OC group. [tCho] was measured versus an external phantom. Mann-Whitney U test and Spearman coefficient were used; data are given as median and interquartile interval. RESULTS: All spectra had good quality. In the nOC group, [tCho] (mM) did not change significantly during MC: 0.8 (0.3-2.4) on day 7, 0.9 (0.4-1.2) on day 14, and 0.4 (0.2-0.8) on day 21 (p = 0.963). In the OC group, [tCho] was 0.7 (0.2-1.7) mM. The between-groups difference was not significant on all days (p ≥ 0.411). All hormones except prolactin changed during MC (p ≤ 0.024). In the OC group, [tCho] showed a borderline correlation with estradiol (r = 0.458, p = 0.056), but no correlation with other hormones (p ≥ 0.128). In the nOC group, [tCho] negatively correlated with prolactin (r = -0.587, p = 0.006) on day 7; positive correlation was found with estradiol on day 14 (r = 0.679, p = 0.001). CONCLUSIONS: A tCho peak can be detected in the normal mammary gland using 3-T 1H-MRS. The [tCho] in healthy volunteers was 0.4-0.9 mM, constant over the MC and independent of OC use

An Innovative Face Emotion Recognition-based Platform by using a Mobile Device as a Virtual Tour

Emotions are the base of human evolution. They help us to survive and to face up all problems of our life. Without emotions human evolution was not possible and we would be in caves. Nowadays, emotions are a very important aspect in different field not only in psychology. They are very important to understand human mind and decision-making process.Emotional tourism is an example of a new way to use emotions analysis. In this field emotions are used to create a most deep experience from the begin of a travel to each steps of the journey. They help tourism to make traveler the protagonist of his travel and not just a spectator.In this paper, we are going to show an app which predicts a travel destination based on user’s mood and facial expressions to specifics visual and auditory trigger to encounter his reactions. This app uses different technology linked together to make this solution versatile and dynamic. It implements different technology modules to perform facial and mood analysis, capturing the image, store image and show all trigger to the user. By adopting this solution is possible to easily upgrade the app and each module can be changed with no large problem adapting it to the current version of the app