611 research outputs found
On the spatial stickiness of UK new firm formation rates
This research explores persistence of new firm formation at the UK NUTS II level for the 1994â2007 period. The results obtained herewith suggest that interregional differences in new firm formation and their determinants are time persistent. The evidence produced shows that past new firm formation rates determine future ones and that, depending on the econometric specification, human capital, local industry structure, sources of external economies and local economic conditions and wealth are significant determinants. The analysis of new firm formation distribution dynamics suggests that whatever changes may arise in the external shape of distribution are not significant and intra-distribution mobility is limited
Examining sustainability performance in the supply chain: The case of the Greek dairy sector
This is the post-print version of the final paper published in Industrial Marketing Management. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2013 Elsevier B.V.This paper evaluates the sustainability performance of the Greek dairy chain and the performance of its individual members by using key indicators in relation to efficiency, flexibility, responsiveness and product quality. We assessed the importance of these indicators based on the relevant perceptions of key members of this chain. A structured questionnaire was developed where nineteen sustainability-related issues were examined. Two hundred and fifty three members of the Greek dairy supply chain responded including breeders, manufacturers, wholesalers, retailers and catering companies. Our findings illustrate the immediate need for improvement in many key sustainability performance indicators. They also show the critical role of large dairy manufacturers who are the âsustainability performance championsâ in this chain and are the driving force for the implementation of many sustainability initiatives.European Unio
On manifolds admitting the consistent Lagrangian formulation for higher spin fields
We study a possibility of Lagrangian formulation for free higher spin bosonic
totally symmetric tensor field on the background manifold characterizing by the
arbitrary metric, vector and third rank tensor fields in framework of BRST
approach. Assuming existence of massless and flat limits in the Lagrangian and
using the most general form of the operators of constraints we show that the
algebra generated by these operators will be closed only for constant curvature
space with no nontrivial coupling to the third rank tensor and the strength of
the vector fields. This result finally proves that the consistent Lagrangian
formulation at the conditions under consideration is possible only in constant
curvature Riemann space.Comment: 11 pages; v2: minor typos corrected, a reference adde
Spin 3 cubic vertices in a frame-like formalism
Till now most of the results on interaction vertices for massless higher spin
fields were obtained in a metric-like formalism using completely symmetric
(spin-)tensors. In this, the Lagrangians turn out to be very complicated and
the main reason is that the higher the spin one want to consider the more
derivatives one has to introduce. In this paper we show that such
investigations can be greatly simplified if one works in a frame-like
formalism. As an illustration we consider massless spin 3 particle and
reconstruct a number of vertices describing its interactions with lower spin 2,
1 and 0 ones. In all cases considered we give explicit expressions for the
Lagrangians and gauge transformations and check that the algebra of gauge
transformations is indeed closed.Comment: 17 pades, no figure
Higher spin interactions with scalar matter on constant curvature spacetimes: conserved current and cubic coupling generating functions
Cubic couplings between a complex scalar field and a tower of symmetric
tensor gauge fields of all ranks are investigated on any constant curvature
spacetime of dimension d>2. Following Noether's method, the gauge fields
interact with the scalar field via minimal coupling to the conserved currents.
A symmetric conserved current, bilinear in the scalar field and containing up
to r derivatives, is obtained for any rank r from its flat spacetime
counterpart in dimension d+1, via a radial dimensional reduction valid
precisely for the mass-square domain of unitarity in (anti) de Sitter spacetime
of dimension d. The infinite collection of conserved currents and cubic
vertices are summarized in a compact form by making use of generating functions
and of the Weyl/Wigner quantization on constant curvature spaces.Comment: 35+1 pages, v2: two references added, typos corrected, enlarged
discussions in Subsection 5.2 and in Conclusion, to appear in JHE
Induced Gravity on RS Branes
It is shown that a localized four-dimensional Einstein term, induced by
quantum corrections, modifies significantly the law of gravity in a
Randall-Sundrum brane world. In particular, the short-distance behavior of
gravity changes from five- to four-dimensional, while, depending on the values
of parameters, there can be an intermediate range where gravity behaves as in
five dimensions. The spectrum of graviton fluctuations around the brane, their
relative importance for the gravitational force, and the relevance of their
emission in the bulk for the brane cosmology are analysed. Finally, constraints
on parameters are derived from energy loss in astrophysical and particle
physics processes.Comment: 20 pages, 1 figure, JHEP.cl
Thermodynamics of the localized D2-D6 system
An exact fully-localized extremal supergravity solution for N_2 D2 branes and
N_6 D6 branes, which is dual to 3-dimensional supersymmetric SU(N_2) gauge
theory with N_6 fundamentals, was found by Cherkis and Hashimoto. In order to
consider the thermal properties of the gauge theory we present the non-extremal
extension of this solution to first order in an expansion near the core of the
D6 branes. We compute the Hawking temperature and the black brane horizon
area/entropy. The leading order entropy, which is proportional to N_2^{3/2}
N_6^{1/2} T_H^2, is not corrected to first order in the expansion. This result
is consistent with the analogous weak-coupling result at the correspondence
point N_2 ~ N_6.Comment: 14 page
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