1,978 research outputs found
Social and alternative banking: project selection and monitoring after the New Basel Capital Accord
Any economic activity calls for the exercise of moral judgement. There are some economic activities that actively promote collective benefit as a primary or secondary aim, and there are others that aim to increase the value of a firm. Investment decisions always have collective impact, but collective returns may be ignored or considered less important in company management if the objective is the maximisation of shareholder wealth. The allocative function exercised by banks in their credit activity may take this into account. Some banks nowadays focus on social profile, while others integrate the traditional approach with this new sensibility. But unfortunately banking regulations governing stability and soundness of the financial system make no mention of the social profile. The New Basel Capital Accord was an opportunity to recognise that bank's objectives may not consist only of the maximisation of shareholder wealth. But it was a missed opportunity, in that it gave advantages to traditional commercial banks and not to banks focussing on collective goals. This paper puts forward proposals for integrating the Basel II framework with profiles of collective bank credit policy. Social credit evaluation methods could help to identify those ethical banks which are more successful in meeting collective objectives. A sustainable credit appraisal methodology could have been examined by the Basel Committee and could have incentivated sustainable banking by giving it specific advantages.social banking, alternative banking, socially responsible investing, investments appraisal, Basel II, new capital accord
Density-Dependent Synthetic Gauge Fields Using Periodically Modulated Interactions
We show that density-dependent synthetic gauge fields may be engineered by
combining periodically modu- lated interactions and Raman-assisted hopping in
spin-dependent optical lattices. These fields lead to a density- dependent
shift of the momentum distribution, may induce superfluid-to-Mott insulator
transitions, and strongly modify correlations in the superfluid regime. We show
that the interplay between the created gauge field and the broken sublattice
symmetry results, as well, in an intriguing behavior at vanishing interactions,
characterized by the appearance of a fractional Mott insulator.Comment: 5 pages, 5 figure
Steering Bose-Einstein condensates despite time symmetry
A Bose-Einstein condensate in an oscillating spatially asymmetric potential
is shown to exhibit a directed current for unbiased initial conditions despite
time symmetry. This phenomenon occurs only if the interaction between atoms,
treated in mean-field approximation, exceeds a critical value. Our findings can
be described with a three-mode model (TMM). These TMM results corroborate well
with a many-body study over a time scale which increases with increasing atom
number. The duration of this time scale probes the validity of the used
mean-field approximation.Comment: 4 pages, 5 figure
Charged Dilaton Black Holes with a Cosmological Constant
The properties of static spherically symmetric black holes, which are either
electrically or magnetically charged, and which are coupled to the dilaton in
the presence of a cosmological constant, are considered. It is shown that such
solutions do not exist if the cosmological constant is positive (in arbitrary
spacetime dimension >= 4). However, asymptotically anti-de Sitter black hole
solutions with a single horizon do exist if the cosmological constant is
negative. These solutions are studied numerically in four dimensions and the
thermodynamic properties of the solutions are derived. The extreme solutions
are found to have zero entropy and infinite temperature for all non-zero values
of the dilaton coupling constant.Comment: 12 pages, epsf, phyzzx, 4 in-text figures incl. (minor typos fixed, 1
reference added
Do naked singularities generically occur in generalized theories of gravity?
A new mechanism for causing naked singularities is found in an effective
superstring theory. We investigate the gravitational collapse in a spherically
symmetric Einstein-Maxwell-dilaton system in the presence of a pure
cosmological constant "potential", where the system has no static black hole
solution. We show that once gravitational collapse occurs in the system, naked
singularities necessarily appear in the sense that the field equations break
down in the domain of outer communications. This suggests that in generalized
theories of gravity, the non-minimally coupled fields generically cause naked
singularities in the process of gravitational collapse if the system has no
static or stationary black hole solution.Comment: 4 pages including 2 eps figures, to be published in Physical Review
Letter
Density-dependent synthetic magnetism for ultracold atoms in optical lattices
10 pags.; 6 figs.; PACS number(s): 67.85.−d, 03.65.Vf, 03.75.Lm© 2015 American Physical Society. Raman-assisted hopping can allow for the creation of density-dependent synthetic magnetism for cold neutral gases in optical lattices. We show that the density-dependent fields lead to a nontrivial interplay between density modulations and chirality. This interplay results in a rich physics for atoms in two-leg ladders, characterized by a density-driven Meissner-superfluid to vortex-superfluid transition, and a nontrivial dependence of the density imbalance between the legs. Density-dependent fields also lead to intriguing physics in square lattices. In particular, it leads to a density-driven transition between a nonchiral and a chiral superfluid, both characterized by nontrivial charge density-wave amplitude. We finally show how the physics due to the density-dependent fields may be easily probed in experiments by monitoring the expansion of doublons and holes in a Mott insulator, which presents a remarkable dependence on quantum fluctuations.We acknowledge support by the cluster of excellence QUEST, the
DFG Research Training Group 1729, the SUTD start-up grant
(Grant No. SRG-EPD-2012-045), and the Spanish Ministry of
Economy and Competitiveness through Grants No. FIS-2012-
34479, No. BES-2010-031607, and No. EEBB-14-09077.Peer Reviewe
Phase sensitive amplification in a highly nonlinear lead-silicate fibre
We experimentally demonstrate phase-sensitive amplification in a highly nonlinear lead-silicate W-type fibre. A phase-sensitive gain swing of 6dB was observed in a 1.56m sample of the fibre for a total launched power of 33dBm
Charged Dilatonic AdS Black Branes in Arbitrary Dimensions
We study electromagnetically charged dilatonic black brane solutions in
arbitrary dimensions with flat transverse spaces, that are asymptotically AdS.
This class of solutions includes spacetimes which possess a bulk region where
the metric is approximately invariant under Lifshitz scalings. Given fixed
asymptotic boundary conditions, we analyze how the behavior of the bulk up to
the horizon varies with the charges and derive the extremality conditions for
these spacetimes.Comment: References update
Controlled transport of matter waves in two-dimensional optical lattices
We propose a method for achieving dynamically controllable transport of
highly mobile matter-wave solitons in a driven two-dimensional optical lattice.
Our numerical analysis based on the mean-field model and the theory based on
the time-averaging approach, demonstrate that a fast time-periodic rocking of
the two-dimensional optical lattice enables efficient stabilization and
manipulation of spatially localized matter wavepackets via induced
reconfigurable mobility channels.Comment: 4 pages, 4 figure
Charged Nariai Black Holes With a Dilaton
The Reissner-Nordstrom-de Sitter black holes of standard Einstein-Maxwell
theory with a cosmological constant have no analogue in dilatonic theories with
a Liouville potential. The only exception are the solutions of maximal mass,
the Charged Nariai solutions. We show that the structure of the solution space
of the Dilatonic Charged Nariai black holes is quite different from the
non-dilatonic case. Its dimensionality depends on the exponential coupling
constants of the dilaton. We discuss the possibility of pair creating such
black holes on a suitable background. We find conditions for the existence of
Charged Nariai solutions in theories with general dilaton potentials, and
consider specifically a massive dilaton.Comment: 20 pages, LaTeX, 4 figures, submitted to Phys. Rev.
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