162,575 research outputs found
Do the gravitational corrections to the beta functions of the quartic and Yukawa couplings have an intrinsic physical meaning?
We study the beta functions of the quartic and Yukawa couplings of General
Relativity and Unimodular Gravity coupled to the and Yukawa
theories with masses. We show that the General Relativity corrections to those
beta functions as obtained from the 1PI functional by using the standard MS
multiplicative renormalization scheme of Dimensional Regularization are gauge
dependent and, further, that they can be removed by a non-multiplicative,
though local, field redefinition. An analogous analysis is carried out when
General Relativity is replaced with Unimodular Gravity. Thus we show that any
claim made about the change in the asymptotic behaviour of the quartic and
Yukawa couplings made by General Relativity and Unimodular Gravity lack
intrinsic physical meaning.Comment: 6 pages, 7 figure
A Reciprocity Result for Projective Indecomposable Modules of Cellular Algebras and BGG Algebras
We show that an adaptation of Landrock's Lemma for symmetric algebras also
holds for cellular algebras and BGG algebras. This is a result relating the
radical layers of any two projective modules. The reason it holds in our
setting is that there is a duality between injective hulls and projective
covers. As a corollary we deduce that BGG reciprocity respects Loewy structure
Hydrodynamics of tire hydroplaning Final report, 1 Jul. 1965 - 30 Jun. 1966
Hydrodynamics including lift and drag forces for aircraft pneumatic tire hydroplanin
Labour Turnover and Firm Performance
We explore the impact of labour turnover on firm performance by analysing the predictions of an extension of the efficiency wage model of Salop (1979) developed by Garino and Martin (2007), which separates incumbent and newly hired workers in the production function. Within this theoretical framework, an exogenous increase in the turnover rate can increase profits if firms do not choose wages unilaterally. We test the theoretical predictions of the model using UK cross-section establishment-level data, the 2004 Workplace and Employee Relations Survey. In accordance with our theoretical priors, the empirical results support the standard inverse relationship between the quit rate and firm performance where firms unilaterally choose the wage and generally support a positive relationship between firm performance and the quit rate where trade unions influence wage setting
Cavitation Inception in Spool Valves
Cavitation has been investigated in directional control valves in order to identify damage mechanisms characteristic of components of aircraft hydraulic systems. Tests have been conducted in a representative metal spool valve and in a model three times larger. Data taken under non-cavitating conditions with both valves showed that the position of the high-velocity annular jet shifts orientation depending upon valve opening and Reynolds number. By means of high-frequency response pressure transducers strategically placed in the valve chamber cavitation could be sensed by the correlation of noise with a cavitation index. The onset of cavitation can be detected by comparing energy spectra for a fixed valve opening and a constant discharge. Another sensitive indicator of cavitation inception is the ratio of cavitating to non-cavitating spectral densities. The incipient cavitation number as defined in this investigation is correlated with the Reynolds number for both valves
Familial hemiplegic migraine with cerebellar ataxia and paroxysmal psychosis
Familial hemiplegic migraine is a rare autosomal dominant disorder associated with stereotypic neurologic au ra phenomena including hemiparesis, So far two chromosomal loci have been identified. Families linked to the chromosome 19 locus display missense mutations within the CACNL1A4 gene. Here we report on a family with familial hemiplegic migraine and cerebellar ataxia with recurrent episodes of acute paranoid psychosis with anxiety and visual hallucinations associated with migraine attacks. Based on the clinical and haplotype evidence indicating linkage to chromosome 19 in this family, we hypothesize that a dysfunction of the mutated calcium channel may be involved not only in the development of hemiplegic migraine but also in the acute psychotic episodes observed in these patients
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