Miracle-dz/UniFAR-FTUs huggingface dataset:
Scanning electron microscopy of cold gases

Ultracold quantum gases offer unique possibilities to study interacting many-body quantum systems. Probing and manipulating such systems with ever increasing degree of control requires novel experimental techniques. Scanning electron microscopy is a high resolution technique which can be used for in situ imaging, single site addressing in optical lattices and precision density engineering. Here, we review recent advances and achievements obtained with this technique and discuss future perspectives.
MID-IR ENHANCED GALAXIES IN THE COMA & VIRGO CLUSTERS: LENTICULARS WITH A HIGH STAR FORMATION RATE

We explore the properties of early-type galaxies (ETGs), including ellipticals (E) and lenticulars (S0), in rich environments, such as clusters of galaxies (Virgo and Coma). The L24/LK distribution of ETGs in both Virgo and Coma clusters shows that some S0s have a much larger L24/LK ratio (0.5 to ∼2 dex) than the bulk of the ETG population. This could be interpreted as an enhanced star formation rate in these lenticulars. We compare the optical colors of galaxies in these two clusters and investigate the nature of these sources with a large L24/LK ratio by looking at their spatial distribution within the cluster, analyzing their optical spectra, and looking at their optical colors compared to late-types. We obtain 10 Coma and 3 Virgo early-type sources with larger L24/LK ratios than the bulk of their population. We call these sources mid-infrared enhanced galaxies (MIEGs). In Coma, they are mostly located in the southwest part of the cluster where a substructure is falling onto the main cluster. MIEGs present a lower g − r ? > color than the rest of the ETG sample because of a blue continuum. We interpret the excess L24/LK ratio as evidence for enhanced star formation induced as a consequence of their infall into the main cluster.
A White Paper on keV sterile neutrino Dark Matter

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved—cosmology, astrophysics, nuclear, and particle physics—in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos.
Dissipative preparation of the exciton and biexciton in a self-assembled quantum dot on picosecond timescales

Pulsed resonant fluorescence is used to probe ultrafast phonon-assisted exciton and biexciton preparation in individual self-assembled InGaAs quantum dots. By driving the system using large area ($\geq10\pi$) near resonant optical pulses, we experimentally demonstrate how phonon mediated dissipation within the manifold of dressed excitonic states can be used to prepare the neutral exciton with a fidelity $\geq 70\%$. By comparing the phonon-assisted preparation with resonant Rabi oscillations we show that the phonon-mediated process provides the higher fidelity preparation for large pulse areas and is less sensitive to pulse area variations. Moreover, by detuning the laser with respect to the exciton transition we map out the spectral density for exciton coupling to the bulk LA-phonon continuum. Similar phonon mediated processes are shown to facilitate direct biexciton preparation via two photon biexciton absorption, with fidelities $>80\%$. Our results are found to be in very good quantitative agreement with simulations that model the quantum dot-phonon bath interactions with Bloch-Redfield theory.
A BAYESIAN ASSESSMENT OF P-VALUES FOR SIGNIFICANCE ESTIMATION OF POWER SPECTRA AND AN ALTERNATIVE PROCEDURE, WITH APPLICATION TO SOLAR NEUTRINO DATA

The usual procedure for estimating the significance of a peak in a power spectrum is to calculate the probability of obtaining that value or a larger value by chance (known as the “p-value”), on the assumption that the time series contains only noise—typically that the measurements are derived from random samplings of a Gaussian distribution. However, since the use of p-values in other contexts is known to be misleading, it seems prudent to examine the implications of using p-values for significance estimation of power spectra. We really need to know the probability that the time series is—or is not—compatible with the “null hypothesis” that the measurements are derived from noise. This probability can be calculated by Bayesian analysis, but this requires one to specify and evaluate a second hypothesis that the time series does contain a contribution other than noise. We show that the requirement that the p-value should be identical to the probability that the null hypothesis is true leads to an unacceptable form for the likelihood function associated with this hypothesis. We claim that, for this reason, the p-value is not an acceptable method for significance estimation of a power spectrum. In order to obtain an acceptable significance estimate, it is necessary to explicitly consider a second hypothesis, and the key challenge is to identify an appropriate likelihood function for this hypothesis. We first propose four simple conditions that it seems reasonable to impose on this function. We then examine a general functional form for the function, and find the simplest form (which has one free parameter) that meets these conditions. We then define two different ways of combining information derived from two independent power estimates. One procedure is to calculate the post-probabilities of the null hypothesis, convert these to odds-values, and sum the log-odds. The second procedure is to combine the p-values using a procedure due to R.A. Fisher, and to calculate the corresponding post-probability and hence the corresponding log-odds. It seems sensible—even if not logically essential—to seek a likelihood function for which the two procedures lead to the same answer. We find that this consistency condition may be satisfied, to good approximation, by a special case of the previously proposed likelihood function. We find that the resulting significance estimates are considerably more conservative than those usually associated with the p-values. As two examples, we apply the new procedure to two recent analyses of solar neutrino data: (1) power spectrum analysis of Super-Kamiokande data and (2) the combined analysis of radiochemical neutrino data and irradiance data.
Estimating cosmological parameters by the simulated data of gravitational waves from the Einstein Telescope

We investigate the constraint ability of the gravitational wave (GW) as the standard siren on the cosmological parameters by using the third-generation gravitational wave detector: the Einstein Telescope. The binary merger of a neutron with either a neutron or black hole is hypothesized to be the progenitor of a short and intense burst of $\ensuremath{\gamma}$ rays; some fraction of those binary mergers could be detected both through electromagnetic radiation and gravitational waves. Thus we can determine both the luminosity distance and redshift of the source separately. We simulate the luminosity distances and redshift measurements from 100 to 1000 GW events. We use two different algorithms to constrain the cosmological parameters. For the Hubble constant ${H}_{0}$ and dark matter density parameter ${\mathrm{\ensuremath{\Omega}}}_{m}$, we adopt the Markov chain Monte Carlo approach. We find that with about 500--600 GW events we can constrain the Hubble constant with an accuracy comparable to Planck temperature data and Planck lensing combined results, while for the dark matter density, GWs alone seem not able to provide the constraints as good as for the Hubble constant; the sensitivity of 1000 GW events is a little lower than that of Planck data. It should require more than 1000 events to match the Planck sensitivity. Yet, for analyzing the more complex dynamical property of dark energy, i.e., the equation of state $w$, we adopt a new powerful nonparametric method: the Gaussian process. We can reconstruct $w$ directly from the observational luminosity distance at every redshift. In the low redshift region, we find that about 700 GW events can give the constraints of $w(z)$ comparable to the constraints of a constant $w$ by Planck data with type-Ia supernovae. Those results show that GWs as the standard sirens to probe the cosmological parameters can provide an independent and complementary alternative to current experiments.
Green Synthesis of Titanium Dioxide Nanoparticles Using Ocimum sanctum Leaf Extract: In Vitro Characterization and Its Healing Efficacy in Diabetic Wounds

Diabetes mellitus is one of the most prevalent metabolic disorders characterized by hyperglycemia due to impaired glucose metabolism. Overproduction of free radicals due to chronic hyperglycemia may cause oxidative stress, which delays wound healing in diabetic conditions. For people with diabetes, this impeded wound healing is one of the predominant reasons for mortality and morbidity. The study aimed to develop an Ocimum sanctum leaf extract-mediated green synthesis of titanium dioxide (TiO2) nanoparticles (NPs) and further incorporate them into 2% chitosan (CS) gel for diabetic wound healing. UV-visible spectrum analysis recorded the sharp peak at 235 and 320 nm, and this was the preliminary sign for the biosynthesis of TiO2 NPs. The FTIR analysis was used to perform a qualitative validation of the biosynthesized TiO2 nanoparticles. XRD analysis indicated the crystallinity of TiO2 NPs in anatase form. Microscopic investigation revealed that TiO2 NPs were spherical and polygonal in shape, with sizes ranging from 75 to 123 nm. The EDX analysis of green synthesized NPs showed the presence of TiO2 NPs, demonstrating the peak of titanium ion and oxygen. The hydrodynamic diameter and polydispersity index (PDI) of the TiO2 NPs were found to be 130.3 nm and 0.237, respectively. The developed TiO2 NPs containing CS gel exhibited the desired thixotropic properties with pseudoplastic behavior. In vivo wound healing studies and histopathological investigations of healed wounds demonstrated the excellent wound-healing efficacy of TiO2 NPs containing CS gel in diabetic rats.
Effect of inhomogeneities on high precision measurements of cosmological distances

We study effects of inhomogeneities on distance measures in an exact relativistic Swiss-cheese model of the universe, focusing on the distance modulus. The model has LCDM background dynamics, and the `holes' are non-symmetric structures described by the Szekeres metric. The Szekeres exact solution of Einstein's equations, which is inhomogeneous and anisotropic, allows us to capture potentially relevant effects on light propagation due to nontrivial evolution of structures in an exact framework. Light beams traversing a single Szekeres structure in different ways can experience either magnification or demagnification, depending on the particular path, and we explore a small additional effect due time evolution of the structures. We study the probability distributions of $\Delta\mu=\mu_{LCDM}-\mu_{SC}$ for sources at different redshifts in various Swiss-cheese constructions, where the light beams travel through a large number of randomly oriented holes with random impact parameters. We find for $\Delta\mu$ the dispersions $0.004\le \sigma_{\Delta\mu} \le 0.008$ mag for sources with redshifts $1.0\le z \le 1.5$, which are smaller than the intrinsic dispersion of, for example, magnitudes of type Ia supernovae. The shapes of the distributions we obtain for our Swiss-cheese constructions are peculiar in the sense that they are not consistently skewed toward the demagnification side, as they are in analyses of lensing in cosmological simulations, reflecting a limitation of these constructions. This could be the result of requiring the continuity of Einstein's equations throughout the overall spacetime patchwork, which imposes the condition that compensating overdense shells must accompany the underdense void regions in the holes. The possibility to explore other uses of these constructions that could circumvent this limitation and lead to different statistics remains open. (Abridged)
GALAXY THREE-POINT CORRELATION FUNCTIONS AND HALO/SUBHALO MODELS

We present measurements of the luminosity-dependent redshift-space three-point correlation functions (3PCFs) for the Sloan Digital Sky Survey Data Release 7 Main galaxy sample. We compare the 3PCF measurements to the predictions from three different halo and subhalo models. One is the halo occupation distribution (HOD) model and the other two are extensions of the subhalo abundance matching model by allowing the central and satellite galaxies to have different occupation distributions in the host halos and subhalos. Parameters in all the models are chosen to best describe the projected and redshift-space two-point correlation functions (2PCFs) of the same set of galaxies. All three model predictions agree well with the 3PCF measurements for the most luminous galaxy sample, while the HOD model better performs in matching the 3PCFs of fainter samples (with luminosity threshold below L*), which is similar in trend to the case of fitting the 2PCFs. The decomposition of the model 3PCFs into contributions from different types of galaxy triplets shows that on small scales the dependence of the 3PCFs on triangle shape is driven by nonlinear redshift-space distortion (and not by the intrinsic halo shape) while on large scales it reflects the filamentary structure. The decomposition also reveals more detailed differences in the three models, which are related to the radial distribution, the mean occupation function, and the velocity distribution of satellite galaxies inside halos. The results suggest that galaxy 3PCFs can further help constrain the above galaxy–halo relation and test theoretical models.
THE CONNECTION BETWEEN THE POSITRON FRACTION ANOMALY AND THE SPECTRAL FEATURES IN GALACTIC COSMIC-RAY HADRONS

Recent data on Galactic cosmic-ray (CR) leptons and hadrons gave rise to two exciting problems: on the lepton side, the origin of the rise of the CR positron fraction e + ? > /(e - ? > + e + ? > ) at ∼10–300 GeV of energy; on the hadron side, the nature of the spectral hardening observed in CR protons and nuclei at ∼TeV energies. The lepton anomaly indicates the existence of a nearby e ± ? > source. It has been proposed that high-energy positrons can be produced inside nearby supernova remnants (SNRs) via interactions of CR hadrons with the ambient medium. A distinctive prediction of this mechanism is a high-energy rise of the boron-to-carbon ratio, which has not been observed. It also requires old SNRs at work (with ineffective magnetic field amplification and slow shock speed) that cannot account for the CR hadronic spectra observed up to the knee energies (∼5 PeV). We propose a new picture where, in addition to such a nearby CR accelerator, the high-energy spectrum of CR hadrons is provided by the large-scale population of SNRs, younger on average, which can efficiently accelerate CRs up to the knee. Under this scenario, the spectral hardening of CR hadrons can be naturally interpreted as the transition between the two components. As we will show, our two-component model breaks the connection between the positron fraction and the boron-to-carbon ratio, which is now predicted to decrease with energy in accordance with the data. Forthcoming data from AMS will be crucial for testing this model.
Dark matter and Wigner's third positive-energy representation class

The almost 7 decades lasting futile attempts to understand the possible physical content of the third Wigner representation class (the infinite spin class) came to a partial solution with the 2006 discovery of existence of string-localized spacetime covariantizations . This has led to a still ongoing vast generalization of renormalizability to fields with arbitrary high spin and a better understanding of the origin of partial invisibility as observed in the confinement of gluons and quarks. The present note explains the total (non-gravitational) invisibility of fields associated to the third Wigner representation class. The last section presents a critical look at the possibility that third class Wigner matter may play a role in dark matter formation.
Astrophysical fluid simulations of thermally ideal gases with non-constant adiabatic index: numerical implementation

An Equation of State (\textit{EoS}) closes the set of fluid equations. Although an ideal EoS with a constant \textit{adiabatic index} $\Gamma$ is the preferred choice due to its simplistic implementation, many astrophysical fluid simulations may benefit from a more sophisticated treatment that can account for diverse chemical processes. Here, we first review the basic thermodynamic principles of a gas mixture in terms of its thermal and caloric EoS by including effects like ionization, dissociation as well as temperature dependent degrees of freedom such as molecular vibrations and rotations. The formulation is revisited in the context of plasmas that are either in equilibrium conditions (local thermodynamic- or collisional excitation- equilibria) or described by non-equilibrium chemistry coupled to optically thin radiative cooling. We then present a numerical implementation of thermally ideal gases obeying a more general caloric EoS with non-constant adiabatic index in Godunov-type numerical schemes.We discuss the necessary modifications to the Riemann solver and to the conversion between total energy and pressure (or vice-versa) routinely invoked in Godunov-type schemes. We then present two different approaches for computing the EoS.The first one employs root-finder methods and it is best suited for EoS in analytical form. The second one leans on lookup table and interpolation and results in a more computationally efficient approach although care must be taken to ensure thermodynamic consistency. A number of selected benchmarks demonstrate that the employment of a non-ideal EoS can lead to important differences in the solution when the temperature range is $500-10^4$ K where dissociation and ionization occur. The implementation of selected EoS introduces additional computational costs although using lookup table methods can significantly reduce the overhead by a factor $3\sim 4$.
Vortex loop operators, M2-branes and holography

We construct vortex loop operators in the three-dimensional N = 6 super- symmetric Chern-Simons theory recently constructed by Aharony, Bergman, Jafferis and Maldacena. These disorder loop operators are specified by a vortex-like singularity for the scalar and gauge fields along a one dimensional curve in spacetime. We identify the 1/2, 1/3 and 1/6 BPS loop operators in the Chern-Simons theory with excitations of M-theory corresponding to M2-branes ending along a curve on the boundary of AdS4 × S 7 /Zk. The vortex loop operators can also be given a purely geometric description in terms of regular "bubbling" solutions of eleven dimensional supergravity which are asymptotically AdS4 × S 7 /Zk.
COSMOS weak-lensing constraints on modified gravity

The observed acceleration of the universe, explained through dark energy, could alternatively be explained through a modification of gravity that would also induce modifications in the evolution of cosmological perturbations. We use new weak lensing data from the COSMOS survey to test for deviations from General Relativity. The departure from GR is parametrized in a model-independent way that consistently parametrizes the two-point cosmic shear amplitude and growth. Using CMB priors, we perform a likelihood analysis. We find constraints on the amplitude of the signal that do not indicate a deviation from General Relativity.
THE IMACS CLUSTER BUILDING SURVEY. V. FURTHER EVIDENCE FOR STARBURST RECYCLING FROM QUANTITATIVE GALAXY MORPHOLOGIES

Using J- and Ks-band imaging obtained as part of the IMACS Cluster Building Survey (ICBS), we measure Sérsic indices for 2160 field and cluster galaxies at 0.31 < z < 0.54. Using both mass- and magnitude-limited samples, we compare the distributions for spectroscopically determined passive, continuously star-forming, starburst, and post-starburst systems and show that previously established spatial and statistical connections between these types extend to their gross morphologies. Outside of cluster cores, we find close structural ties between starburst and continuously star-forming, as well as post-starburst and passive types, but not between starbursts and post-starbursts. These results independently support two conclusions presented in Paper II of this series: (1) most starbursts are the product of a non-disruptive triggering mechanism that is insensitive to global environment, such as minor mergers; (2) starbursts and post-starbursts generally represent transient phases in the lives of “normal” star-forming and quiescent galaxies, respectively, originating from and returning to these systems in closed “recycling” loops. In this picture, spectroscopically identified post-starbursts constitute a minority of all recently terminated starbursts, largely ruling out the typical starburst as a quenching event in all but the densest environments.
Level of helium enhancement among M3's horizontal-branch stars

(Abridged) The color and luminosity distribution of horizontal branch (HB) stars in globular clusters are sensitive probes of their original helium abundances. However, recent analyses based on visual and near-ultraviolet (UV) CMDs have provided conflicting results. To clarify the situation, we address the optimum ranges of applicability (in terms of the $T_{eff}$ range covered by the HB stars) for visual and near-UV CMDs, as far as application of this HB $Y$ test goes. We consider both Stromgren and Hubble Space Telescope (HST) bandpasses. Our results indicate that the distributions of HB stars in the y vs (b-y) plane can be a reliable indicator of the He content in cool blue HB (BHB) stars, particularly when a differential comparison between blue and red HB stars is carried out in the range $T_{eff}<8300$K. Conversely, we demonstrate that CMDs using the F336W filter have a much less straightforward interpretation at the cool end of the BHB, as the distributions of HB stars in the F336W vs (F336W-F555W) plane are affected by a triple degeneracy effect. In other words, the position of an HB star is exactly the same, for a given chemical composition, for multiple combinations of the parameters $Y$, $M_{HB}$, and age along the HB evolutionary track. Other HST UV filters do not appear to be as severely affected by this degeneracy effect, to which visual bandpasses are also immune. We do find, on the other hand, that such near-UV CMDs can be extremely useful for the hottest stars along the cool BHB end. Based on a reanalysis of the distribution of HB stars in the y vs (b-y) plane, we find that the coolest among the BHB stars in M3 are likely enhanced in helium by $\Delta Y\approx 0.01$, compared with the red HB stars in the same cluster. Using near-UV HST photometry we find evidence of a progressive increase in $Y$ with increasing temperature, reaching $\Delta Y=0.02$ at $T_{eff}=10900$K.