7,909 research outputs found
Complexified coherent states and quantum evolution with non-Hermitian Hamiltonians
The complex geometry underlying the Schr\"odinger dynamics of coherent states
for non-Hermitian Hamiltonians is investigated. In particular two seemingly
contradictory approaches are compared: (i) a complex WKB formalism, for which
the centres of coherent states naturally evolve along complex trajectories,
which leads to a class of complexified coherent states; (ii) the investigation
of the dynamical equations for the real expectation values of position and
momentum, for which an Ehrenfest theorem has been derived in a previous paper,
yielding real but non-Hamiltonian classical dynamics on phase space for the
real centres of coherent states. Both approaches become exact for quadratic
Hamiltonians. The apparent contradiction is resolved building on an observation
by Huber, Heller and Littlejohn, that complexified coherent states are
equivalent if their centres lie on a specific complex Lagrangian manifold. A
rich underlying complex symplectic geometry is unravelled. In particular a
natural complex structure is identified that defines a projection from complex
to real phase space, mapping complexified coherent states to their real
equivalents.Comment: 18 pages, small improvements made, similar to published versio
Grotesque and Scenography. Virtual reconstruction of anthropomorphic supports within the entry of Philip II in Antwerp (1549)
This paper aims to analyse the presence of a motif from the Flemish repertoire of the grotesque in the configuration of a unique type of anthropomorphic support used in the ephemeral architecture erected on Philip II of Spain’s entry into Antwerp in 1549. The support consists of a figure that, resembling an atlante or a caryatid, supports a cornice, but whose peculiarity is that the body is partially embedded in the surface of the façade, fulfilling a more decorative function than strictly tectonic. The development of this analysis is based on the concept of visual culture, but this approach also constitutes an attempt for developing a virtual reconstruction of this particular motif in its artistic context.Universidad de Málaga. Campus de Excelencia Internacional andalucía Tech
Financial Reporting – from Responsibilities to the Quality Assurance Systems
Particularities of the financial reporting exigencies suppose realistic approaches which are under the sign of at least two targets: on the one hand the correct understanding of the role of a relevant and reliable financial reporting and of the accountability for financial statements preparing and presenting, and on the other hand the increase in the users interest in the quality of the financial information provided by the financial reporting. There is a specific inter-relationship between the two categories of factors which should impose for the possible lacks in the process of preparing the financial statements to be identified during the qualified reviews and of other forms of quality assurance of the accounting information quality so that when this becomes public, when reaching the users, to answer to their demands. Being aware of the existence of a national creativity area in the process of assimilating the European norms and the international standards in the area, the current study intends to point out the main benchmarks for the financial reporting exigencies.financial reporting, conformity, financial statements, quality assurance systems, financial reporting users.
Heterogeneity in Bank Pricing Policies: The Czech Evidence
In this paper, we estimate the interest rate pass-through from money market to bank interest rates using various heterogeneous panel cointegration techniques to address bank heterogeneity. Based on our micro-level data from the Czech Republic, the results indicate that the nature of interest rate pass-through differs across banks in the short term (rendering estimators that constrain coefficients across groups to be identical inconsistent) and becomes homogeneous across banks only in the long term, supporting the notion of the law of one price. Mortgage rates and firm rates typically adjust to money market changes, but often less than fully in the long run. Large corporate loans have a smaller mark-up than small loans. Consumer rates have a high mark-up and are not found to exhibit a cointegration relationship with money market rates. Next, we examine how bank characteristics determine the nature of interest rate pass-through in a cross-section of Czech banks. We find evidence for relationship lending, as banks with a stable pool of deposits smooth interest rates and require a higher spread as compensation. Large banks are not found to price their products less competitively. Greater credit risk increases vulnerability to money market shocks.Bank pricing policies, financial structure, monetary transmission.
Propagation of Gaussian beams in the presence of gain and loss
We consider the propagation of Gaussian beams in a waveguide with gain and
loss in the paraxial approximation governed by the Schr\"odinger equation. We
derive equations of motion for the beam in the semiclassical limit that are
valid when the waveguide profile is locally well approximated by quadratic
functions. For Hermitian systems, without any loss or gain, these dynamics are
given by Hamilton's equations for the center of the beam and its conjugate
momentum. Adding gain and/or loss to the waveguide introduces a non-Hermitian
component, causing the width of the Gaussian beam to play an important role in
its propagation. Here we show how the width affects the motion of the beam and
how this may be used to filter Gaussian beams located at the same initial
position based on their width
Russian Doll Renormalization Group and Superconductivity
We show that an extension of the standard BCS Hamiltonian leads to an
infinite number of condensates with different energy gaps and self-similar
properties, described by a cyclic RG flow of the BCS coupling constant which
returns to its original value after a finite RG time.Comment: 4 pages, 2 figs, RevTex
Reconstructing the image of the ideal city in Renaissance painting and theatre: Its influence in specific urban environments. Digital technology and visual culture
This paper shows a virtual reconstruction based on a comparative study between scenography designs of urban views, and similar landscapes used in painting, in order to eventually find correspondences with specific urban environments.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
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