Lattice approaches to dilute Fermi gases: Legacy of broken Galilean invariance

In the dilute limit, the properties of fermionic lattice models with short-range attractive interactions converge to those of a dilute Fermi gas in continuum space. We investigate this connection using mean-field and we show that the existence of a finite lattice spacing has consequences down to very small densities. In particular we show that the reduced translational invariance associated to the lattice periodicity has a pivotal role in the finite-density corrections to the universal zero-density limit. For a parabolic dispersion with a sharp cut-off, we provide an analytical expression for the leading-order corrections in the whole BCS-BEC crossover. These corrections, which stem only from the unavoidable cut-off, contribute to the leading-order corrections to the relevant observables. In a generic lattice we find a universal power-law behavior $n^{1/3}$ which leads to significant corrections already for small densities. Our results pose strong constraints on lattice extrapolations of dilute Fermi gas properties.Comment: 10 pages, 7 figure

\uabOGNE CANZONA TENE \u2019O RITURNELLO\ubb. RIFLESSIONI SU COME SONO FATTE LE CANZONI NAPOLETANE

Nel saggio vengono analizzate le forme della canzone napoletana

New interesting moss records from the Pollino National Park (Southern Italy).

Some interesting moss records in Pollino National Park, noteworthy protected area of the southern Apennines, are reported. Among them, Mnium spinosum and Brachythecium tommasinii are new to southern Italian peninsula, Grimmia laevigata, G. Montana, G. tergestina, G. trichophylla and Orthotrichum pumilum are new to Basilicata region, and, finally, Campylidium sommerfeltii is rare in southern Italy and little known in Mediterranean area

New or interesting regional bryophyte records for Italian bryoflora

Based on recent bryophyte collections five records are added to the bryophyte flora of some Italian regions. The hepatic Riccia beyrichiana is new to Campania, Archidium alternifolium, Campylopus introflexus and Hedwigia stellata are new mosses to Lazio and Hylocomium splendens to Basilicata. In addition, the presence of Campylopus atrovirens and Pleuridium acuminatum in Lazio is confirmed after more than half a centur

Magnetism and domain formation in SU(3)-symmetric multi-species Fermi mixtures

We study the phase diagram of an SU(3)-symmetric mixture of three-component ultracold fermions with attractive interactions in an optical lattice, including the additional effect on the mixture of an effective three-body constraint induced by three-body losses. We address the properties of the system in $D \geq 2$ by using dynamical mean-field theory and variational Monte Carlo techniques. The phase diagram of the model shows a strong interplay between magnetism and superfluidity. In the absence of the three-body constraint (no losses), the system undergoes a phase transition from a color superfluid phase to a trionic phase, which shows additional particle density modulations at half-filling. Away from the particle-hole symmetric point the color superfluid phase is always spontaneously magnetized, leading to the formation of different color superfluid domains in systems where the total number of particles of each species is conserved. This can be seen as the SU(3) symmetric realization of a more general tendency to phase-separation in three-component Fermi mixtures. The three-body constraint strongly disfavors the trionic phase, stabilizing a (fully magnetized) color superfluid also at strong coupling. With increasing temperature we observe a transition to a non-magnetized SU(3) Fermi liquid phase.Comment: 36 pages, 17 figures; Corrected typo

A novel Digital OTA topology with 66-dB DC Gain and 12.3-kHz Bandwidth

The paper introduces an enhanced digital OTA topology which allows increasing the DC gain thanks to the adoption of an inverter-based output stage. Moreover, a new equivalent small-signal model is proposed which allows to simplify the circuit analysis and paves the way to new frequency compensation strategies. Designed using a 28-nm standard CMOS technology and working at 0.3-V power supply, post-layout simulations show a 66-dB gain and a 12.3-kHz gain bandwidth product while driving a 250-pF capacitive load. As compared to other ultra-low-voltage OTAs in literature, an increase of small and large signal performance, respect to area occupation, equal to 4.6X and 1.5X, respectively, is obtained

Bonnard´s representation of the perception of substance

Artists are said to be like neuroscientists able to exploit the capacities of the brain to generate aesthetic experience (Zeki, 2001). Pierre Bonnard (1867-1947) has been recognized as one of the greatest and most enigmatic masters of the 20th century painting. For his understanding of the eye movements, attentional shifts mechanism and the representation in his paintings of the complexity of the physiological process of vision perception, something that he famously referred to as "the transcription of the adventures of the optic nerve", he is considered a revolutionary painter. Our recent eye movements study on Bonnard's paintings evidences a "temporal-extended" mechanism in the control of scanpaths that refers to a progression of the scanpath pattern during repetitive viewings and supports the phenomenon of late emotional response which was one of the artist's artistic and perceptual objective