Exploring Critical Overdensity Thresholds in Inflationary Models of Primordial Black Holes Formation

In this paper we study the production of Primordial Black Holes (PBHs) from inflation in order to explain the Dark Mater (DM) in the Universe. The evaluation of the fractional PBHs abundance to DM is sensitive to the value of the threshold $\mathrm{\delta_c}$ and the exact value of $\mathrm{\delta_c}$ is sensitive to the specific shape of the cosmological fluctuations. Different mechanisms producing PBHs lead to different thresholds and hence to different fractional abundances of PBHs. In this study, we examine various classes of inflationary models proposed in the existing literature to elucidate the formation of PBHs and we evaluate numerically the associated threshold values. Having evaluated the thresholds we compute the abundances of PBHs to DM using the Press Schecter approach and the Peak Theory. Given the influence of different power spectra on the thresholds, we investigate whether these inflationary models can successfully account for a significant fraction of DM. Moreover, we provide suggested values for the critical threshold. By examining the interplay between inflationary models, threshold values, and PBH abundances, our study aims to shed light on the viability of PBHs as a candidate for DM and contributes to the ongoing discussion regarding the nature of DM in the UniverseComment: 17 pages, 4 figure

The CMSSM Survives Planck, the LHC, LUX-ZEPLIN, Fermi-LAT, H.E.S.S. and IceCube

We revisit the viability of the CMSSM, searching for regions of parameter space that yield a neutralino dark matter density compatible with Planck measurements, as well as LHC constraints including sparticle searches and the mass of the Higgs boson, recent direct limits on spin-independent and -dependent dark matter scattering from the LUX-ZEPLIN (LZ) experiment, the indirect constraints from Fermi-LAT and H.E.S.S. on dark matter annihilations to photons in dwarf spheroidal galaxies and the Galactic Centre, and the IceCube limits on muons from annihilations to neutrinos in the Sun. For representative values of $\tan \beta$ and $A_0$ we map in detail the Planck-compatible strips in CMSSM parameter planes, which exhibit multiple distinctive features for large $\tan \beta$, $A_0 = 0$ and $\mu > 0$, and identify portions of the strips that survive all the phenomenological constraints. We find that the most powerful constraint is that from $m_h$, followed by the LZ limit on spin-independent scattering, whereas sparticle searches at the LHC and indirect dark matter searches are less restrictive. Most of the surviving CMSSM parameter space features a Higgsino-like dark matter particle with a mass $\sim 1000-1100$ GeV, which could best be probed with future direct searches for dark matter scattering.Comment: 44 pages, 20 figures, journal version to appear in EPJ-

A preliminary study on the effects Cu, Pb and Zn contamination of soils on community structure and certain life-history traits of oribatids from urban areas

ABSTRACT The effect of pollution of urban softs by traffic exhausts on oribatid mites was studied along a traffic gradient of the city of Thessaloniki. Although the population density of the main orbatid species appeared increased in polluted areas, the total oribatid numbers were reduced due to the reduction in species richness. The highest species diversity was recorded in moderately polluted areas. The morphometric characteristics as well as certain life-history traits did no correlate with the level of traffic influence. Nevertheless, these characteristics were considered important for the understanding of the pollution impact on life in soils. Moderate body size, sexual reproduction, increased reproductive effort and wide habitat preferences characterize species in urban sites. Scheloribates latipes and Tectocepheus sarekensis can be used as bioindicators for Pb and Zn pollution of softs, respectively

Direct measurements of the effects of salt and surfactant on interaction forces between colloidal particles at water-oil interfaces

The forces between colloidal particles at a decane-water interface, in the presence of low concentrations of a monovalent salt (NaCl) and of the surfactant sodium dodecylsulfate (SDS) in the aqueous subphase, have been studied using laser tweezers. In the absence of electrolyte and surfactant, particle interactions exhibit a long-range repulsion, yet the variation of the interaction for different particle pairs is found to be considerable. Averaging over several particle pairs was hence found to be necessary to obtain reliable assessment of the effects of salt and surfactant. It has previously been suggested that the repulsion is consistent with electrostatic interactions between a small number of dissociated charges in the oil phase, leading to a decay with distance to the power -4 and an absence of any effect of electrolyte concentration. However, the present work demonstrates that increasing the electrolyte concentration does yield, on average, a reduction of the magnitude of the interaction force with electrolyte concentration. This implies that charges on the water side also contribute significantly to the electrostatic interactions. An increase in the concentration of SDS leads to a similar decrease of the interaction force. Moreover the repulsion at fixed SDS concentrations decreases over longer times. Finally, measurements of three-body interactions provide insight into the anisotropic nature of the interactions. The unique time-dependent and anisotropic interactions between particles at the oil-water interface allow tailoring of the aggregation kinetics and structure of the suspension structure.Comment: Submitted to Langmui

Identification of gut bacteria such as Lactobacillus johnsonii that disseminate to systemic tissues of wild type and MyD88-/- mice

In healthy hosts the gut microbiota is restricted to gut tissues by several barriers some of which require MyD88-dependent innate immune sensor pathways. Nevertheless, some gut taxa have been reported to disseminate to systemic tissues. However, the extent to which this normally occurs during homeostasis in healthy organisms is still unknown. In this study, we recovered viable gut bacteria from systemic tissues of healthy wild type (WT) and MyD8

Brachionus rotundiformis tschugunoff, 1921 from the brachionus plicatilis species complex (Rotifera: Monogononta): A new record from galápagos archipelago, Ecuador

The presence of the rotifer species Brachionus rotundiformis from the B. plicatilis species complex in Lake Arcturo, a saline lake in the Genovesa Island of the Galápagos Islands, is here reported. This is the first record of the species for the rotifer fauna of Ecuador as well as of the species complex to the Galápagos Islands. This finding is consistent with the idea of high dispersion capacity, and of cosmopolitan distribution of this species complex. Because Genovesa Island is uninhabited, passive transport by wind currents and zoochory by migrant birds seem to emerge as the most plausible factors in this process of colonization. Integrative studies on the morphological variations, genetic, molecular, and ecological aspects are still required to further understand the process of dispersion and the ecology of this member of the B. plicatilis species complex in this remote and isolated locality, and the exact taxonomical position of the island’s population to the other members of the complex.</p