3,148 research outputs found
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 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
Pittori e musici nell\u2019Italia del Cinque e Seicento
Two paintings by G. A. Sirani show
a close link between poetry, painting
and music, as recognized in early
modern Italy. The article explores the
nature of the link between painting
and music according to three levels:
theory (pythagorean proportions and
reflections on the craft of painting),
composition (a term used both by
painters and musicians), everyday life
(painters playing and singing,
musicians drawing and painting)
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 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 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
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