293 research outputs found
Infinite-dimensional -adic groups, semigroups of double cosets, and inner functions on Bruhat--Tits builldings
We construct -adic analogs of operator colligations and their
characteristic functions. Consider a -adic group , its subgroup , and the subgroup
embedded to diagonally. We show that double cosets
admit a structure of a semigroup, acts naturally in -fixed vectors
of unitary representations of . For each double coset we assign a
'characteristic function', which sends a certain Bruhat--Tits building to
another building (buildings are finite-dimensional); image of the distinguished
boundary is contained in the distinguished boundary. The latter building admits
a structure of (Nazarov) semigroup, the product in corresponds to a
point-wise product of characteristic functions.Comment: new version of the paper, 47pp, 3 figure
A Method Based on a Nonlinear Generalized Heisenberg Algebra to Study the Molecular Vibrational Spectrum
We propose a method, based on a Generalized Heisenberg Algebra (GHA), to
reproduce the anharmonic spectrum of diatomic molecules. The theoretical
spectrum generated by GHA allows us to fit the experimental data and to obtain
the dissociation energy for the carbon monoxide molecule. Our outcomes are more
accurate than the standard models used to study molecular vibrations, namely
the Morse and the -oscillator models and comparable to the perturbed Morse
model proposed by Huffaker \cite{hf}, for the first experimental levels. The
dissociation energy obtained here is more accurate than all previous models
Challenges of beta-deformation
A brief review of problems, arising in the study of the beta-deformation,
also known as "refinement", which appears as a central difficult element in a
number of related modern subjects: beta \neq 1 is responsible for deviation
from free fermions in 2d conformal theories, from symmetric omega-backgrounds
with epsilon_2 = - epsilon_1 in instanton sums in 4d SYM theories, from
eigenvalue matrix models to beta-ensembles, from HOMFLY to super-polynomials in
Chern-Simons theory, from quantum groups to elliptic and hyperbolic algebras
etc. The main attention is paid to the context of AGT relation and its possible
generalizations.Comment: 20 page
Optimality and distortionary lobbying: regulating tobacco consumption
We examine policies directed at regulating tobacco consumption through three types of instruments: (i) an excise tax hindering consumption by increasing the price of cigarettes, (ii) prevention programs helping consumers to make choices that are more time consistent when trading-off the current pleasure from smoking and its future health harms, and (iii) smoking bans directly restricting consumption. First, on normative grounds, we focus on the optimal design of public policies maximizing the economy’s surplus. Second, in a positive perspective, we investigate how the lobbying activities of the tobacco industry, of smokers, and of anti-tobacco organizations may distort government intervention
Vote buying or (political) business (cycles) as usual?
We study the short-run effect of elections on monetary aggregates in a sample of 85 low and middle income democracies (1975-2009). We find an increase in the growth rate of M1 during election months of about one tenth of a standard deviation. A similar effect can neither be detected in established OECD democracies nor in other months. The effect is larger in democracies with many poor and uneducated voters, and in Sub-Saharan Africa, Latin America, and in East-Asia and the Pacific. We argue that the election month monetary expansion is related to systemic vote buying which requires significant amounts of cash to be disbursed right before elections. The finely timed increase in M1 is consistent with this; is inconsistent with a monetary cycle aimed at creating an election time boom; and it cannot be, fully, accounted for by alternative explanations
Exclusive photoproduction of pi degrees up to large values of Mandelstam variables s, t, and u with CLAS
Exclusive photoproduction cross sections have been measured for the process
with the Dalitz decay final state
using tagged photon energies in the range of GeV.
The complete angular distribution of the final state , for the entire
photon energy range up to large values of and , has been measured for
the first time. The data obtained show that the cross section , at
mid to large angles, decreases with energy as . This is in
agreement with the perturbative QCD quark counting rule prediction of . Paradoxically, the size of angular distribution of measured cross sections
is greatly underestimated by the QCD based Generalized Parton Distribution
mechanism at highest available invariant energy GeV. At the same
time, the Regge exchange based models for photoproduction are more
consistent with experimental data.Comment: 7 pages, 6 figure
Underperformance of African protected area networks and the case for new conservation models : insights from Zambia
Many African protected areas (PAs) are not functioning effectively. We reviewed the performance of Zambia’s PA network
and provide insights into how their effectiveness might be improved. Zambia’s PAs are under-performing in ecological,
economic and social terms. Reasons include: a) rapidly expanding human populations, poverty and open-access systems in
Game Management Areas (GMAs) resulting in widespread bushmeat poaching and habitat encroachment; b) underfunding
of the Zambia Wildlife Authority (ZAWA) resulting in inadequate law enforcement; c) reliance of ZAWA on extracting
revenues from GMAs to cover operational costs which has prevented proper devolution of user-rights over wildlife to
communities; d) on-going marginalization of communities from legal benefits from wildlife; e) under-development of the
photo-tourism industry with the effect that earnings are limited to a fraction of the PA network; f) unfavourable terms and
corruption which discourage good practice and adequate investment by hunting operators in GMAs; g) blurred
responsibilities regarding anti-poaching in GMAs resulting in under-investment by all stakeholders. The combined effect of
these challenges has been a major reduction in wildlife densities in most PAs and the loss of habitat in GMAs. Wildlife fares
better in areas with investment from the private and/or NGO sector and where human settlement is absent. There is a need
for: elevated government funding for ZAWA; greater international donor investment in protected area management; a shift
in the role of ZAWA such that they focus primarily on national parks while facilitating the development of wildlife-based
land uses by other stakeholders elsewhere; and new models for the functioning of GMAs based on joint-ventures between
communities and the private and/or NGO sector. Such joint-ventures should provide defined communities with ownership
of land, user-rights over wildlife and aim to attract long-term private/donor investment. These recommendations are
relevant for many of the under-funded PAs occurring in other African countries.The Wildlife Producers Association of Zambia. CJT was funded with a Claude Leon Fellowship.http://www.plosone.orgam201
Underperformance of African protected area networks and the case for new conservation models : insights from Zambia
Many African protected areas (PAs) are not functioning effectively. We reviewed the performance of Zambia’s PA network
and provide insights into how their effectiveness might be improved. Zambia’s PAs are under-performing in ecological,
economic and social terms. Reasons include: a) rapidly expanding human populations, poverty and open-access systems in
Game Management Areas (GMAs) resulting in widespread bushmeat poaching and habitat encroachment; b) underfunding
of the Zambia Wildlife Authority (ZAWA) resulting in inadequate law enforcement; c) reliance of ZAWA on extracting
revenues from GMAs to cover operational costs which has prevented proper devolution of user-rights over wildlife to
communities; d) on-going marginalization of communities from legal benefits from wildlife; e) under-development of the
photo-tourism industry with the effect that earnings are limited to a fraction of the PA network; f) unfavourable terms and
corruption which discourage good practice and adequate investment by hunting operators in GMAs; g) blurred
responsibilities regarding anti-poaching in GMAs resulting in under-investment by all stakeholders. The combined effect of
these challenges has been a major reduction in wildlife densities in most PAs and the loss of habitat in GMAs. Wildlife fares
better in areas with investment from the private and/or NGO sector and where human settlement is absent. There is a need
for: elevated government funding for ZAWA; greater international donor investment in protected area management; a shift
in the role of ZAWA such that they focus primarily on national parks while facilitating the development of wildlife-based
land uses by other stakeholders elsewhere; and new models for the functioning of GMAs based on joint-ventures between
communities and the private and/or NGO sector. Such joint-ventures should provide defined communities with ownership
of land, user-rights over wildlife and aim to attract long-term private/donor investment. These recommendations are
relevant for many of the under-funded PAs occurring in other African countries.The Wildlife Producers Association of Zambia. CJT was funded with a Claude Leon Fellowship.http://www.plosone.orgam201
A catalog of new Blazar candidates with Open Universe by High School students
Blazars are active galactic nuclei whose ultra-relativistic jets are
coaligned with the observer direction. They emit throughout the whole e.m.
spectrum, from radio waves to VHE gamma rays. Not all blazars are discovered.
In this work, we propose a catalog of 54 new candidates based on the
association of HE gamma ray emission and radio, X-ray an optical signatures.
The relevance of this work is also that it was performed by four high school
students from the Liceo Scientifico Statale Ugo Morin in Venice, Italy using
the open-source platform Open Universe, in collaboration with the University of
Padova. The framework of the activity is the Italian MIUR PCTO programme. The
success of this citizen-science experience and results are hereafter reported
and discussed.Comment: Proceedings of the 12th Cosmic Ray International Symposium (CRIS
2022), 12-16 September 2022, Naples (Italy). Send correspondence to:
[email protected], [email protected]
How Effective are Policies to Reduce Gasoline Consumption? Evaluating a Quasi-Natural Experiment in Spain
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