8,453 research outputs found
The classical double copy for Taub-NUT spacetime
The double copy is a much-studied relationship between gauge theory and
gravity amplitudes. Recently, this was generalised to an infinite family of
classical solutions to Einstein's equations, namely stationary Kerr-Schild
geometries. In this paper, we extend this to the Taub-NUT solution in gravity,
which has a double Kerr-Schild form. The single copy of this solution is a
dyon, whose electric and magnetic charges are related to the mass and NUT
charge in the gravity theory. Finally, we find hints that the classical double
copy extends to curved background geometries.Comment: 13 pages, no figures. Minor edits to match journal versio
Estado Confusional Agudo após Corticoterapia Inalada
Background: The connection between corticotherapy and neuropsychiatric symptoms is
widely known, being one of the first questions
we need to assess when presenting with first
episode psychiatric symptoms or confusional
state.
Aims: To date, data on cases related to inhaled
corticotherapy and neuropsychiatric effects is
scarce. In this paper we describe a rare case in
a young woman.
Methods: The clinical case presented led us
to try to understand the data published on the
subject in order to discuss it in greater length.
Results and Conclusions: We present and
discuss a 27-year-old patient’s case, with no
previous psychiatric disease, who was admitted to our Psychiatric ward after the onset of
severe acute behavioural disturbance characterized by aggressiveness, visual and auditory
hallucinatory activity, misidentification and
altered conscience status. It was later found
that seven days earlier she had been prescribed
inhaled corticotherapy for a minor respiratory
infection. A few days after corticotherapy withdrawal, the clinical symptoms improved significantly.info:eu-repo/semantics/publishedVersio
Representation of Nelson Algebras by Rough Sets Determined by Quasiorders
In this paper, we show that every quasiorder induces a Nelson algebra
such that the underlying rough set lattice is algebraic. We
note that is a three-valued {\L}ukasiewicz algebra if and only if
is an equivalence. Our main result says that if is a Nelson
algebra defined on an algebraic lattice, then there exists a set and a
quasiorder on such that .Comment: 16 page
Generalized quantum field theory: perturbative computation and perspectives
We analyze some consequences of two possible interpretations of the action of
the ladder operators emerging from generalized Heisenberg algebras in the
framework of the second quantized formalism. Within the first interpretation we
construct a quantum field theory that creates at any space-time point particles
described by a q-deformed Heisenberg algebra and we compute the propagator and
a specific first order scattering process. Concerning the second one, we draw
attention to the possibility of constructing this theory where each state of a
generalized Heisenberg algebra is interpreted as a particle with different
mass.Comment: 19 page
Some boundary effects in quantum field theory
We have constructed a quantum field theory in a finite box, with periodic
boundary conditions, using the hypothesis that particles living in a finite box
are created and/or annihilated by the creation and/or annihilation operators,
respectively, of a quantum harmonic oscillator on a circle. An expression for
the effective coupling constant is obtained showing explicitly its dependence
on the dimension of the box.Comment: 12 pages, Late
Band inversion driven by electronic correlations at the (111) LaAlO/SrTiO interface
Quantum confinement at complex oxide interfaces establishes an intricate
hierarchy of the strongly correlated -orbitals which is widely recognized as
a source of emergent physics. The most prominent example is the (001)
LaAlO/SrTiO(LAO/STO) interface, which features a dome-shaped phase
diagram of superconducting critical temperature and spin-orbit coupling (SOC)
as a function of electrostatic doping, arising from a selective occupancy of
orbitals of different character. Here we study (111)-oriented LAO/STO
interfaces - where the three orbitals contribute equally to the
sub-band states caused by confinement - and investigate the impact of this
unique feature on electronic transport. We show that transport occurs through
two sets of electron-like sub-bands, and the carrier density of one of the sets
shows a non-monotonic dependence on the sample conductance. Using tight-binding
modeling, we demonstrate that this behavior stems from a band inversion driven
by on-site Coulomb interactions. The balanced contribution of all
orbitals to electronic transport is shown to result in strong SOC with reduced
electrostatic modulation.Comment: 5 pages, 4 figures, (+ supplemental material
Two-dimensional superconductivity at the (111)LaAlO/SrTiO interface
We report on the discovery and transport study of the superconducting ground
state present at the (111)LaAlO/SrTiO interface. The superconducting
transition is consistent with a Berezinskii-Kosterlitz-Thouless transition and
its 2D nature is further corroborated by the anisotropy of the critical
magnetic field, as calculated by Tinkham. The estimated superconducting layer
thickness and coherence length are 10 nm and 60 nm, respectively. The results
of this work provide a new platform to clarify the microscopic details of
superconductivity at LaAlO/SrTiO interfaces, in particular in what
concerns the link with orbital symmetry.Comment: 4 pages, 4 figure
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