209,707 research outputs found
Hermitian forms for affine Hecke algebras
We study star operations for Iwahori-Hecke algebras and invariant hermitian
forms for finite dimensional modules over (graded) affine Hecke algebras with a
view towards a unitarity algorithm.Comment: 29 pages, preliminary version. v2: the classification of star
operations for the graded Hecke algebras and the construction of hermitian
forms in the Iwahori case via Bernstein's projectives have been removed from
this preprint and they will make the basis of a new pape
Star operations for affine Hecke algebras
In this paper, we consider the star operations for (graded) affine Hecke
algebras which preserve certain natural filtrations. We show that, up to inner
conjugation, there are only two such star operations for the graded Hecke
algebra: the first, denoted , corresponds to the usual star operation
from reductive -adic groups, and the second, denoted can be
regarded as the analogue of the compact star operation of a real group
considered by \cite{ALTV}. We explain how the star operation appears
naturally in the Iwahori-spherical setting of -adic groups via the
endomorphism algebras of Bernstein projectives. We also prove certain results
about the signature of -invariant forms and, in particular, about
-unitary simple modules.Comment: 27 pages; section 3 and parts of sections 2 and 5 were previously
contained in the first version of the preprint arXiv:1312.331
Benchmarking Utility Clean Energy Deployment: 2016
Benchmarking Utility Clean Energy Deployment: 2016 provides a window into how the global transition toward clean energy is playing out in the U.S. electric power sector. Specifically, it reveals the extent to which 30 of the largest U.S. investor-owned electric utility holding companies are increasingly deploying clean energy resources to meet customer needs.Benchmarking these companies provides an opportunity for transparent reporting and analysis of important industry trends. It fills a knowledge gap by offering utilities, regulators, investors, policymakers and other stakeholders consistent and comparable information on which to base their decisions. And it provides perspective on which utilities are best positioned in a shifting policy landscape, including likely implementation of the U.S. EPA's Clean Power Plan aimed at reducing carbon pollution from power plants
Ladder representations of GL(n,Q_p)
In this paper, we recover certain known results about the ladder
representations of GL(n, Q_p) defined and studied by Lapid, Minguez, and Tadic.
We work in the equivalent setting of graded Hecke algebra modules. Using the
Arakawa-Suzuki functor from category O to graded Hecke algebra modules, we show
that the determinantal formula proved by Lapid-Minguez and Tadic is a direct
consequence of the BGG resolution of finite dimensional simple gl(n)-modules.
We make a connection between the semisimplicity of Hecke algebra modules,
unitarity with respect to a certain hermitian form, and ladder representations.Comment: 14 page
The importance of distinct modeling strategies for gene and gene-specific treatment effects in hierarchical models for microarray data
When analyzing microarray data, hierarchical models are often used to share
information across genes when estimating means and variances or identifying
differential expression. Many methods utilize some form of the two-level
hierarchical model structure suggested by Kendziorski et al. [Stat. Med. (2003)
22 3899-3914] in which the first level describes the distribution of latent
mean expression levels among genes and among differentially expressed
treatments within a gene. The second level describes the conditional
distribution, given a latent mean, of repeated observations for a single gene
and treatment. Many of these models, including those used in Kendziorski's et
al. [Stat. Med. (2003) 22 3899-3914] EBarrays package, assume that expression
level changes due to treatment effects have the same distribution as expression
level changes from gene to gene. We present empirical evidence that this
assumption is often inadequate and propose three-level hierarchical models as
extensions to the two-level log-normal based EBarrays models to address this
inadequacy. We demonstrate that use of our three-level models dramatically
changes analysis results for a variety of microarray data sets and verify the
validity and improved performance of our suggested method in a series of
simulation studies. We also illustrate the importance of accounting for the
uncertainty of gene-specific error variance estimates when using hierarchical
models to identify differentially expressed genes.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS535 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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