312 research outputs found
Braids inside the Birman-Wenzl-Murakami algebra
We determine the Zariski closure of the representations of the braid groups
that factorize through the Birman-Wenzl-Murakami algebra, for generic values of
the parameters . For of modulus 1 and close to 1, we prove
that these representations are unitarizable, thus deducing the topological
closure of the image when in addition are algebraically independent
Infinitesimal Hecke Algebras II
For W a finite (2-)reflection group and B its (generalized) braid group, we
determine the Zariski closure of the image of B inside the corresponding
Iwahori-Hecke algebra. The Lie algebra of this closure is reductive and
generated in the group algebra of W by the reflections of W. We determine its
decomposition in simple factors. In case W is a Coxeter group, we prove that
the representations involved are unitarizable when the parameters of the
representations have modulus 1 and are close to 1. We consequently determine
the topological closure in this case
The Complier Pays Principle: The Limits of Fiscal Approaches Toward Sustainable Forest Management
This paper examines the role and impact of taxation on sustainable forest management. It is shown that fiscal instruments neither reinforce nor substitute for traditional regulatory approaches and can actually undermine sustainability. The paper uses the reasoning at the root of the Faustmann solution to draw conclusions on the incentives for sustainable tropical forest exploitation. It proposes a bond mechanism as an alternative market-based instrument to encourage sustainable forest logging while reducing monitoring costs. Copyright 2001, International Monetary Fund
Convergence in law in the second Wiener/Wigner chaos
Let L be the class of limiting laws associated with sequences in the second
Wiener chaos. We exhibit a large subset L_0 of L satisfying that, for any
F_infinity in L_0, the convergence of only a finite number of cumulants
suffices to imply the convergence in law of any sequence in the second Wiener
chaos to F_infinity. This result is in the spirit of the seminal paper by
Nualart and Peccati, in which the authors discovered the surprising fact that
convergence in law for sequences of multiple Wiener-It\^o integrals to the
Gaussian is equivalent to convergence of just the fourth cumulant. Also, we
offer analogues of this result in the case of free Brownian motion and double
Wigner integrals, in the context of free probability.Comment: 14 pages. This version corrects an error which, unfortunately,
appears in the published version in EC
Electromagnetically induced transparency of ultralong-range Rydberg molecules
We study the impact of Rydberg molecule formation on the storage and
retrieval of Rydberg polaritons in an ultracold atomic medium. We observe
coherent revivals appearing in the retrieval efficiency of stored photons that
originate from simultaneous excitation of Rydberg atoms and Rydberg molecules
in the system with subsequent interference between the possible storage paths.
We show that over a large range of principal quantum numbers the observed
results can be described by a two-state model including only the atomic Rydberg
state and the Rydberg dimer molecule state. At higher principal quantum numbers
the influence of polyatomic molecules becomes relevant and the dynamics of the
system undergoes a transition from coherent evolution of a few-state system to
an effective dephasing into a continuum of molecular states.Comment: Submitted to PR
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