On the Ricci tensor in type II B string theory

Let $\nabla$ be a metric connection with totally skew-symmetric torsion \T on a Riemannian manifold. Given a spinor field $\Psi$ and a dilaton function $\Phi$, the basic equations in type II B string theory are \bdm \nabla \Psi = 0, \quad \delta(\T) = a \cdot \big(d \Phi \haken \T \big), \quad \T \cdot \Psi = b \cdot d \Phi \cdot \Psi + \mu \cdot \Psi . \edm We derive some relations between the length ||\T||^2 of the torsion form, the scalar curvature of $\nabla$, the dilaton function $\Phi$ and the parameters $a,b,\mu$. The main results deal with the divergence of the Ricci tensor \Ric^{\nabla} of the connection. In particular, if the supersymmetry $\Psi$ is non-trivial and if the conditions \bdm (d \Phi \haken \T) \haken \T = 0, \quad \delta^{\nabla}(d \T) \cdot \Psi = 0 \edm hold, then the energy-momentum tensor is divergence-free. We show that the latter condition is satisfied in many examples constructed out of special geometries. A special case is $a = b$. Then the divergence of the energy-momentum tensor vanishes if and only if one condition \delta^{\nabla}(d \T) \cdot \Psi = 0 holds. Strong models (d \T = 0) have this property, but there are examples with \delta^{\nabla}(d \T) \neq 0 and \delta^{\nabla}(d \T) \cdot \Psi = 0.Comment: 9 pages, Latex2

Optimisation of age at first calving in Karan Fries cattle

The study was conducted on the performance records of age at first calving (AFC) spread over a period of 15 years on Karan Fries crossbred cattle maintained at Livestock Research Centre. Data of 676 cows were collected and analysed by Least Squares Technique to examine the effect of non-genetic factors on age at first calving. Period of birth was classified into 5 periods (I-V) and season of calving into 4 seasons (winter, summer, rainy and autumn) to see the effect of non-genetic factors on age at first calving. Effect of period of birth was significant on age at first calving while season of calving showed non-significant effect on age at first calving. The overall least squares mean of age at first calving was 1043.40±6.64 days. For the optimisation of age at first calving with regard to milk productivity, analysis was carried out by class interval method. Age at first calving was classified into 7 classes and its average means of milk yield were obtained by using Least Squares Technique where optimum level of age at first calving was obtained at 885–1100 days based on higher milk yield and numbers of animal observed in different classes. From the study, it was concluded that optimum age at first calving could be achieved through proper nutrition and management practices. However, to determine the optimum level of age at first calving, much emphasis should be given to maximum profit rather than maximizing milk production

Party-group relations in new southern European democracies in the crisis era

UID/CPO/04627/2013 PTDC/IVC-CPO/1864/2014publishersversionpublishe

The odd side of torsion geometry

We introduce and study a notion of `Sasaki with torsion structure' (ST) as an odd-dimensional analogue of K\"ahler with torsion geometry (KT). These are normal almost contact metric manifolds that admit a unique compatible connection with 3-form torsion. Any odd-dimensional compact Lie group is shown to admit such a structure; in this case the structure is left-invariant and has closed torsion form. We illustrate the relation between ST structures and other generalizations of Sasaki geometry, and explain how some standard constructions in Sasaki geometry can be adapted to this setting. In particular, we relate the ST structure to a KT structure on the space of leaves, and show that both the cylinder and the cone over an ST manifold are KT, although only the cylinder behaves well with respect to closedness of the torsion form. Finally, we introduce a notion of `G-moment map'. We provide criteria based on equivariant cohomology ensuring the existence of these maps, and then apply them as a tool for reducing ST structures.Comment: 34 pages; v2: added a small generalization (Proposition 3.6) of the cone construction; two references added. To appear on Ann. Mat. Pura App

From parliamentary pay to party funding: the acceptability of informal institutions in advanced democracies

While direct state funding of political parties has been a prominent theme in cross-national research over the last decade, we still know little about party strategies to access state resources that are not explicitly earmarked for partisan usage. This paper looks at one widespread but often overlooked informal party practice: the ‘taxing’ of MP salaries, i.e., the regular transfer of fixed salary shares to party coffers. Building on notions of informal institutions developed in work on new democracies, our theoretical approach specifies factors that shape the acceptability of this legally non-enforceable intra-organisational practice. It is tested through a selection model applied to a unique data set covering 124 parties across 19 advanced democracies. Controlling for a range of party- and institutional-level variables, we find that the presence of a taxing rule and the collection of demanding tax shares are more common in leftist parties (high internal acceptability) and in systems in which the penetration of state institutions by political parties is intense (high external acceptability)