647 research outputs found
Hochschild cohomology of torus-equivariant D-modules
We discuss the Hochschild cohomology of the category of D-modules associated
to an algebraic stack. In particular we describe the Hochschild cohomology of
the category of torus-equivariant D-modules as the cohomology of a D-module on
the loop space of the quotient stack. Finally, we give an approach for
understanding the Hochschild cohomology of D-modules on general stacks via a
relative compactification of the diagonal. This work is motivated by a desire
to understand the support theory (in the sense of Benson-Iyengar-Krause) of
D-modules on stacks.Comment: Minor edit
The de Rham functor for logarithmic D-modules
In the first part we deepen the six-functor theory of (holonomic) logarithmic
D-modules, in particular with respect to duality and pushforward along
projective morphisms. Then, inspired by work of Ogus, we define a logarithmic
analogue of the de Rham functor, sending logarithmic D-modules to certain
graded sheaves on the so-called Kato-Nakayama space. For holonomic modules we
show that the associated sheaves have finitely generated stalks and that the de
Rham functor intertwines duality for D-modules with a version of
Poincar\'e-Verdier duality on the Kato-Nakayama space. Finally, we explain how
the grading on the Kato-Nakayama space is related to the classical
Kashiwara-Malgrange V-filtration for holonomic D-modules.Comment: 37 page
Graded topological spaces
We introduce the notion of a "graded topological space": a topological space
endowed with a sheaf of abelian groups which we think of as a sheaf of
gradings. Any object living on a graded topological space will be graded by
this sheaf of abelian groups. We work out the fundamentals of sheaf theory and
Poincar\'e-Verdier duality for such spaces
Holonomic and perverse logarithmic D-modules
We introduce the notion of a holonomic D-module on a smooth (idealized)
logarithmic scheme and show that Verdier duality can be extended to this
context. In contrast to the classical case, the pushforward of a holonomic
module along an open immersion is in general not holonomic. We introduce a
"perverse" t-structure on the category of coherent logarithmic D-modules which
makes the dualizing functor t-exact on holonomic modules. This allows us to
transfer some of the formalism from the classical setting and in particular
show that every holonomic module on an open subscheme can be extended to a
holonomic module on the whole space. Conversely this t-exactness characterizes
holonomic modules among all coherent logarithmic D-modules. We also introduce
logarithmic versions of the Gabber and Kashiwara-Malgrange filtrations.Comment: 30 page
EC budget support: thumbs up or down?
Budget support is a form of macro-economic financial assistance that is designed to prioritise the fight against poverty and the achievement of the Millennium Development Goals (MDGs). The European Commission (EC) is providing more and more budget support under the Cotonou Partnership Agreement (CPA), which structures the provision of assistance by the European Union (EU) to the African, Caribbean and Pacific (ACP) countries. The EC also provides macro-economic support through its cooperation agreements with a number of non-ACP countries, for which it is now also introducing budget support.
During the course of its work in the ACP regions, the European Centre for Development Policy Management (ECDPM) was approached by parliamentarians, representatives of non-governmental organisations and partner government officials, all of whom had certain questions to ask about the background to and operation of budget support. These actors regard budget support as an increasingly important mechanism for development cooperation, and one that has potentially far-reaching implications for their work. At the same time, it is a relatively new mechanism, is poorly understood and is driven by a relatively small group of experts in aid agencies and partner country finance or planning ministries.
We have prepared this Discussion Paper in response to these queries. Our aim is to give policy-makers and practitioners in-depth information on the nature and potential of, and the constraints associated with, budget support as a development cooperation modality. The paper explains the complex nature of budget support and its implications for the actors involved, as well as highlighting issues that have a bearing on its success.
Budget support creates opportunities that are not always fully appreciated by its critics. At the same time, it creates risks which tend to be downplayed by its supporters. Against this background, this paper also aims to contribute to this intensely debated issue by providing a balanced view for those seeking to understand its complexities.
As this is intended to be a relatively brief paper, it is limited to key policy issues and the challenges arising from recent experiences with budget support. For this reason, we have not devoted much space to discussing the issue of sector budget support. We advise the reader to consult the bibliography for more detailed information on the practice and technicalities of this rapidly evolving mechanism.
Finally, it is important to recognise that the move towards budget support has aroused many questions among partner government officials, donor agencies, consultants and academic institutes, which tend to feed into the production of specialist documents assessing approaches and experiences. For this reason, this paper can do no more than to describe the current state of a rapidly evolving debate and practice. We hope to be able to follow up this initial study and produce further publications on specific issues, tailored to the needs of individual ACP audiences, as part of our future work
Tracing a standard language in Austria using methodological microvariations of Verbal and Matched Guise Technique
Based on the key hypothesis, that there are heterogeneous conceptualizations of “standardness” within the German speaking countries, this paper both methodologically and empirically tangles main aspects on “standard in Austria” from the perspective of perceptual variationist linguistics. Two series of comprehensive listener judgment tests based on 536 informants, considering different sociolinguistic parameters and assumptions on model speakers, indicate shiftings away from competing (country-specific) conceptualizations towards heterogeneous dimensions of “standard in Austria” with complex evaluative patterns
Revealing the pure confinement effect in glass-forming liquids by dynamic mechanical analysis
Many molecular glass forming liquids show a shift of the glass transition Tg
to lower temperatures when the liquid is confined into mesoporous host
matrices. Two contrary explanations for this effect are given in literature:
First, confinement induced acceleration of the dynamics of the molecules leads
to an effective downshift of Tg increasing with decreasing pore size. Secondly,
due to thermal mismatch between the liquid and the surrounding host matrix,
negative pressure develops inside the pores with decreasing temperature, which
also shifts Tg to lower temperatures. Here we present novel dynamic mechanical
analysis measurements of the glass forming liquid salol in Vycor and Gelsil
with pore sizes of d = 2.6, 5.0 and 7.5 nm. The dynamic complex elastic
susceptibility data can be consistently described with the assumption of two
relaxation processes inside the pores: A surface induced slowed down relaxation
due to interaction with rough pore interfaces and a second relaxation within
the core of the pores. This core relaxation time is reduced with decreasing
pore size d, leading to a downshift of Tg in perfect agreement with recent DSC
measurements
Violence and birth outcomes: evidence from homicides in Brazil
This paper uses microdata from Brazilian natality and mortality vital statistics between 2000 and 2010 to estimate the impact of in-utero exposure to local violence - measured by homicide rates - on birth outcomes. The estimates shows that exposure to violence during the first trimester of pregnancy leads to a small but precisely estimated increase in the risk of low birthweight and prematurity. Effects are found in both rural areas, where homicides are rare, and in urban areas, where violence is endemic. Our estimates imply that homicides in Brazil are responsible for at least 0.5 percent of the incidence of low birthweight (<=2.5 kg) and 3 percent of the incidence of extremely low birthweight (<=1 kg)
- …