1,695 research outputs found
Good potentials for almost isomorphism of countable state Markov shifts
Almost isomorphism is an equivalence relation on countable state Markov
shifts which provides a strong version of Borel conjugacy; still, for mixing
SPR shifts, entropy is a complete invariant of almost isomorphism. In this
paper, we establish a class of potentials on countable state Markov shifts
whose thermodynamic formalism is respected by almost isomorphism
Almost isomorphism for countable state Markov shifts
Countable state Markov shifts are a natural generalization of the well-known
subshifts of finite type. They are the subject of current research both for
their own sake and as models for smooth dynamical systems. In this paper, we
investigate their almost isomorphism and entropy conjugacy and obtain a
complete classification for the especially important class of strongly positive
recurrent Markov shifts. This gives a complete classification up to entropy
conjugacy of the natural extensions of smooth entropy expanding maps, including
all smooth interval maps with non-zero topological entropy
Photoinduced Electron Pairing in a Driven Cavity
We demonstrate how virtual scattering of laser photons inside a cavity via two-photon processes can induce controllable long-range electron interactions in two-dimensional materials. We show that laser light that is red (blue) detuned from the cavity yields attractive (repulsive) interactions whose strength is proportional to the laser intensity. Furthermore, we find that the interactions are not screened effectively except at very low frequencies. For realistic cavity parameters, laser-induced heating of the electrons by inelastic photon scattering is suppressed and coherent electron interactions dominate. When the interactions are attractive, they cause an instability in the Cooper channel at a temperature proportional to the square root of the driving intensity. Our results provide a novel route for engineering electron interactions in a wide range of two-dimensional materials including AB-stacked bilayer graphene and the conducting interface between LaAlO3 and SrTiO3
Numerical study of a banded precipitation event over Italy
Satellite images of 30 October 2008 show the development
over north-central Italy of rainbands and multiple
waves during a strong south-westerly wind episode
associated with a deepening synoptic trough and
cold front passage.
The event was studied by means of the ISAC model chain constituted
of the hydrostatic model BOLAM and the nested non-hydrostatic model
MOLOCH at 1.1 km resolution.
Diagnostics of model output was performed to reveal the
physical origin of the dynamical features and precipitation
field as simulated.
Based on our results we propose a theoretical framework in
which symmetric instability underlies some of the observed
precipitation patterns
Numerical study of a banded precipitation event over Italy
Satellite images of 30 October 2008 show the development
over north-central Italy of rainbands and multiple
waves during a strong south-westerly wind episode
associated with a deepening synoptic trough and
cold front passage.
The event was studied by means of the ISAC model chain constituted
of the hydrostatic model BOLAM and the nested non-hydrostatic model
MOLOCH at 1.1 km resolution.
Diagnostics of model output was performed to reveal the
physical origin of the dynamical features and precipitation
field as simulated.
Based on our results we propose a theoretical framework in
which symmetric instability underlies some of the observed
precipitation patterns
Recommended from our members
The pathophysiology of migraine: year 2005
Migraine is a complex patholophysiology in which both central and peripheral components of the trigeminal pain pathway probably play a significant role, both in the symptoms and signs of the attack and in the mechanisms of action of antimigraine compounds, such as triptans, which constitute the most important therapy for aborting migraine pain and posses several mechanisms on 5–HT receptor–mediated actions. The experimental neurogenic inflammation model represents a simple procedure to obtain preliminary information on well characterized receptortargeted drugs. The apparent paradox observed with certain drugs that are shown to be effective in this model but not in clinical trials offers the opportunity to better manipulate structure–activity to obtain the best pharmacological profile using an array of experimental models. The observation that nitric oxide donors induce migraine–like pain in migraineours and that nitric oxide plays a pivotal role in the control of several functions in the central nervous system, has prompted the use of such molecules for better understanding the pathophysiology of migraine attacks. A link between central and peripheral components of the trigeminal pain pathway is provided by the observation that cortical spreading depression in the rat activates trigeminovascular afferents and induces a series of cortical meningeal and brainstem events consistent with the development of headache. Studies in humans support the hypothesis that cortical spreading depression underlies migraine.aura. Therefore, tt is possible that visual, motor or sensory aura might be responsible for the generation of the pain through the above mechanism
Pressure tuning of light-induced superconductivity in K3C60
Optical excitation at terahertz frequencies has emerged as an effective means
to manipulate complex solids dynamically. In the molecular solid K3C60,
coherent excitation of intramolecular vibrations was shown to transform the
high temperature metal into a non-equilibrium state with the optical
conductivity of a superconductor. Here we tune this effect with hydrostatic
pressure, and we find it to disappear around 0.3 GPa. Reduction with pressure
underscores the similarity with the equilibrium superconducting phase of K3C60,
in which a larger electronic bandwidth is detrimental for pairing. Crucially,
our observation excludes alternative interpretations based on a high-mobility
metallic phase. The pressure dependence also suggests that transient, incipient
superconductivity occurs far above the 150 K hypothesised previously, and
rather extends all the way to room temperature.Comment: 33 pages, 17 figures, 2 table
The Italian Consensus Conference on Pain in Neurorehabilitation
Pain is frequent in several neurological conditions, such as stroke, Parkinson’s disease, multiple sclerosis, diabetic neuropathy, but it is often underestimated and therefore untreated or not successfully treated. Pain reduces quality of life, it may be the cause of adaptive disorders (such as anxiety and depression) and, in patients undergoing rehabilitation, it may negatively impact rehabilitation procedures and hamper the outcome. Unfortunately, there are no significant data regarding the impact of pain in neurorehabilitation patients and what would be the impact of an appropriate pain treatment on rehabilitation outcome. Accordingly, there are no guidelines providing indications on how to treat pain in patients with pain during rehabilitation treatment and thereafter. Given this background, and to comply with the Italian law 38 released on 2010 by the Italian Ministry of Health to guarantee adequate care and treatment of patients with pain both in hospital and in primary care, the Italian Society for Neurological Rehabilitation (SIRN) along with the Italian Society for Physical and Rehabilitative Medicine (SIMFER), promoted a work-in-progress platform, the Italian Consensus Conference on Pain in Neurorehabilitation (ICCPNR)
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