507 research outputs found
An adjunction formula for the Emerton-Jacquet functor
The EmertonâJacquet functor is a tool for studying locally analytic representations of p-adic Lie groups. It provides a way to access the theory of p-adic automorphic forms. Here we give an adjunction formula for the EmertonâJacquet functor, relating it directly to locally analytic inductions, under a strict hypothesis that we call non-critical. We also further study the relationship to socles of principal series in the non-critical setting
Biomasse microbienne et "statut organique" des sols tropicaux : exemple d'un sol vénézuélien des Llanos sous différents systÚmes de culture
National audienc
Progress in the development of a S RETGEM-based detector for an early forest fire warning system
In this paper we present a prototype of a Strip Resistive Thick GEM
photosensitive gaseous detector filled with Ne and ethylferrocene vapours at a
total pressure of 1 atm for an early forest fire detection system. Tests show
that it is one hundred times more sensitive than the best commercial
ultraviolet flame detectors and therefore, it is able to reliably detect a
flame of 1.5x1.5x1.5 m3 at a distance of about 1km. An additional and unique
feature of this detector is its imaging capability, which in combination with
other techniques, may significantly reduce false fire alarms when operating in
an automatic mode.
Preliminary results conducted with air filled photosensitive gaseous
detectors are also presented. The approach main advantages include both the
simplicity of manufacturing and affordability of construction materials such as
plastics and glues specifically reducing detector production cost. The
sensitivity of these air filled detectors at certain conditions may be as high
as those filled with Ne and EF. Long term test results of such sealed detectors
indicate a significant progress in this direction.
We believe that our detectors utilized in addition to other flame and smoke
sensors will exceptionally increase the sensitivity of forest fire detection
systems. Our future efforts will be focused on attempts to commercialize such
detectors utilizing our aforementioned findings.Comment: Presented at the International Conference on Micropattern gaseous
detectors, Crete, Greece, June 200
The classification of irreducible admissible mod p representations of a p-adic GL_n
Let F be a finite extension of Q_p. Using the mod p Satake transform, we
define what it means for an irreducible admissible smooth representation of an
F-split p-adic reductive group over \bar F_p to be supersingular. We then give
the classification of irreducible admissible smooth GL_n(F)-representations
over \bar F_p in terms of supersingular representations. As a consequence we
deduce that supersingular is the same as supercuspidal. These results
generalise the work of Barthel-Livne for n = 2. For general split reductive
groups we obtain similar results under stronger hypotheses.Comment: 55 pages, to appear in Inventiones Mathematica
Even Galois Representations and the Fontaine--Mazur conjecture II
We prove, under mild hypotheses, that there are no irreducible
two-dimensional_even_ Galois representations of \Gal(\Qbar/\Q) which are de
Rham with distinct Hodge--Tate weights. This removes the "ordinary" hypothesis
required in previous work of the author. We construct examples of irreducible
two-dimensional residual representations that have no characteristic zero
geometric (= de Rham) deformations.Comment: Updated to take into account suggestions of the referee; the main
theorems remain unchange
Universal deformation rings for the symmetric group S_4
Let k be an algebraically closed field of characteristic 2, and let W be the
ring of infinite Witt vectors over k. Let S_4 denote the symmetric group on 4
letters. We determine the universal deformation ring R(S_4,V) for every
kS_4-module V which has stable endomorphism ring k and show that R(S_4,V) is
isomorphic to either k, or W[t]/(t^2,2t), or the group ring W[Z/2]. This gives
a positive answer in this case to a question raised by the first author and
Chinburg whether the universal deformation ring of a representation of a finite
group with stable endomorphism ring k is always isomorphic to a subquotient
ring of the group ring over W of a defect group of the modular block associated
to the representation.Comment: 12 pages, 2 figure
ANTIULCEROGENIC AND ANTIULCER ACTIVITIES OF DISSOTIS THOLLONII (MELASTOMATACEAE) LEAVES IN RATS
Objective: Dissotis thollonii is used in Cameroonian ethnomedicine to cure diseases such as inflammations, pregnancy control, diarrhea and gastric ulcer. The aqueous and methanol leaf extracts were evaluated for their anti ulcerogenic and antiulcer activities.Methods: The extracts were administered at the doses of 125, 250 and 500 mg/kg to evaluate their effects on gastric ulcer induced by the HCl/ethanol mixture, indomethacin and acetic acid in rats. Ranitidine, Maalox and Misoprostol were used as standard drugs. Histopathological examination and nitric oxide level was performed to evaluate the basic action mechanism of Dissotis thollonii.Results: Oral administration of the plant dose-dependently prevented HCl/ethanol-induced gastric ulcers (72.15 to 100 % for aqueous extract and 68.78 to 89.60 % for methanol extract), Indomethacin (51.13 to 100 % for aqueous extract and-32.33 to 58.45 % for methanol extract). The extracts also promoted the healing and cicatrization process in chronic gastric ulcer induced by acetic acid and increased the NO level in plasma. Histological studies of the gastric wall revealed that ulcer control group exhibited severe damage of the gastric mucosa, compared to rats pre-treated with extracts, which comparatively showed gastric mucosal protection.Conclusion: Dissotis thollonii possess protective and healing activities in rats. The anti ulcerogenic activity may be attributed to the stimulation of the prostaglandins synthesis and antiulcer property to increase NO level in plasma. Histological investigation of gastric lesion shows that the plant stimulates the cicatrizing process. These results supported the ethnomedicinal uses of Dissotis thollonii in the treatment of gastric ulcers.Ă
On a Conjecture of Rapoport and Zink
In their book Rapoport and Zink constructed rigid analytic period spaces
for Fontaine's filtered isocrystals, and period morphisms from PEL
moduli spaces of -divisible groups to some of these period spaces. They
conjectured the existence of an \'etale bijective morphism of
rigid analytic spaces and of a universal local system of -vector spaces on
. For Hodge-Tate weights and we construct in this article an
intrinsic Berkovich open subspace of and the universal local
system on . We conjecture that the rigid-analytic space associated with
is the maximal possible , and that is connected. We give
evidence for these conjectures and we show that for those period spaces
possessing PEL period morphisms, equals the image of the period morphism.
Then our local system is the rational Tate module of the universal
-divisible group and enjoys additional functoriality properties. We show
that only in exceptional cases equals all of and when the
Shimura group is we determine all these cases.Comment: v2: 48 pages; many new results added, v3: final version that will
appear in Inventiones Mathematica
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