12,271 research outputs found
K-orbit closures on G/B as universal degeneracy loci for flagged vector bundles with symmetric or skew-symmetric bilinear form
We use equivariant localization and divided difference operators to determine
formulas for the torus-equivariant fundamental cohomology classes of -orbit
closures on the flag variety , where G = GL(n,\C), and where is one
of the symmetric subgroups O(n,\C) or Sp(n,\C). We realize these orbit
closures as universal degeneracy loci for a vector bundle over a variety
equipped with a single flag of subbundles and a nondegenerate symmetric or
skew-symmetric bilinear form taking values in the trivial bundle. We describe
how our equivariant formulas can be interpreted as giving formulas for the
classes of such loci in terms of the Chern classes of the various bundles.Comment: Minor revisions and corrections suggested by referees. Final version,
to appear in Transformation Group
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Trends in life cycle greenhouse gas emissions of future light duty electric vehicles
The majority of previous studies examining life cycle greenhouse gas (LCGHG) emissions of battery electric vehicles (BEVs) have focused on efficiency-oriented vehicle designs with limited battery capacities. However, two dominant trends in the US BEV market make these studies increasingly obsolete: sales show significant increases in battery capacity and attendant range and are increasingly dominated by large luxury or high-performance vehicles. In addition, an era of new use and ownership models may mean significant changes to vehicle utilization, and the carbon intensity of electricity is expected to decrease. Thus, the question is whether these trends significantly alter our expectations of future BEV LCGHG emissions. To answer this question, three archetypal vehicle designs for the year 2025 along with scenarios for increased range and different use models are simulated in an LCGHG model: an efficiency-oriented compact vehicle; a high performance luxury sedan; and a luxury sport utility vehicle. While production emissions are less than 10% of LCGHG emissions for today's gasoline vehicles, they account for about 40% for a BEV, and as much as two-thirds of a future BEV operated on a primarily renewable grid. Larger battery systems and low utilization do not outweigh expected reductions in emissions from electricity used for vehicle charging. These trends could be exacerbated by increasing BEV market shares for larger vehicles. However, larger battery systems could reduce per-mile emissions of BEVs in high mileage applications, like on-demand ride sharing or shared vehicle fleets, meaning that trends in use patterns may countervail those in BEV design
Local unitary invariants for multipartite quantum systems
A method is presented to obtain local unitary invariants for multipartite
quantum systems consisting of fermions or distinguishable particles. The
invariants are organized into infinite families, in particular, the
generalization to higher dimensional single particle Hilbert spaces is
straightforward. Many well-known invariants and their generalizations are also
included.Comment: 13 page
MODELING COUPON VALUES FOR READY-TO-EAT BREAKFAST CEREALS
A theoretical framework is developed to highlight the significant determinants of coupon values. A fixed effects panel data model is fitted with data from the breakfast cereal industry. The explanatory variables include own retail price, brand loyalty, brand market share, rival coupon redemptions, and firm and product type indicators.coupons, ready-to-eat breakfast cereals, panel data model, Consumer/Household Economics, Research Methods/ Statistical Methods,
Useful entanglement can be extracted from all nonseparable states
We consider entanglement distillation from a single-copy of a multipartite
state, and instead of rates we analyze the "quality" of the distilled
entanglement. This "quality" is quantified by the fidelity with the GHZ-state.
We show that each not fully-separable state can increase the "quality"
of the entanglement distilled from other states, no matter how weakly entangled
is . We also generalize this to the case where the goal is distilling
states different than the GHZ. These results provide new insights on the
geometry of the set of separable states and its dual (the set of entanglement
witnesses).Comment: 7 page
Character Formulae and Partition Functions in Higher Dimensional Conformal Field Theory
A discussion of character formulae for positive energy unitary irreducible
representations of the the conformal group is given, employing Verma modules
and Weyl group reflections. Product formulae for various conformal group
representations are found. These include generalisations of those found by
Flato and Fronsdal for SO(3,2). In even dimensions the products for free
representations split into two types depending on whether the dimension is
divisible by four or not.Comment: 43 pages, uses harvmac,version 2 2 references added, minor typos
correcte
Schur Q-functions and degeneracy locus formulas for morphisms with symmetries
We give closed-form formulas for the fundamental classes of degeneracy loci
associated with vector bundle maps given locally by (not necessary square)
matrices which are symmetric (resp. skew-symmetric) w.r.t. the main diagonal.
Our description uses essentially Schur Q-polynomials of a bundle, and is based
on a certain push-forward formula for these polynomials in a Grassmann bundle.Comment: 22 pages, AMSTEX, misprints corrected, exposition improved. to appear
in the Proceedings of Intersection Theory Conference in Bologna, "Progress in
Mathematics", Birkhause
Poincar\'e and sl(2) algebras of order 3
In this paper we initiate a general classification for Lie algebras of order
3 and we give all Lie algebras of order 3 based on
and the Poincar\'e algebra in four-dimensions. We then
set the basis of the theory of the deformations (in the Gerstenhaber sense) and
contractions for Lie algebras of order 3.Comment: Title and presentation change
A Local Cooperative's Financial and Strategic Analysis of the Evaluation of Potential Merger Partners
This is a two-part teaching case developed through in-person interviews which were conducted with the managers of locally owned farm supply/grain marketing cooperatives in Indiana and Colorado in the spring of 2000. The case has been written so that each part can be used individually or together and can also be used in either the undergraduate classroom or in extension programming with cooperative managers and directors. Part I focuses on how to use financial analysis in business reorganization decisions and Part II focuses on how to analyze alternative business reorganization possibilities from a strategic management perspective.Cooperatives, Mergers, Evaluation of alternative business strategies, Agribusiness,
Instrument calibrates low gas-rate flowmeters
Electronically measuring the transit time of a soap bubble carried by the gas stream between two fixed points in a burette calibrates flowmeters used for measuring low gas-flow rates
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