Precision constraints on the top-quark effective field theory at future lepton colliders

We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the $e^+e^-\to bW^+\:\bar bW^-$ process. Statistically optimal observables are exploited to constrain simultaneously and efficiently all relevant operators. Their constraining power is sufficient for quadratic effective-field-theory contributions to have negligible impact on limits which are therefore basis independent. This is contrasted with the measurements of cross sections and forward-backward asymmetries. An overall measure of constraints strength, the global determinant parameter, is used to determine which run parameters impose the strongest restriction on the multidimensional effective-field-theory parameter space.Comment: 5 pages, contribution to DIS 2017 proceeding

Equidistribution towards the bifurcation current I : Multipliers and degree d polynomials

In the moduli space of degree d polynomials, the set Per\_n(w) of classes [f] for which f admits a cycle of exact period n and multiplier w is known to be an algebraic hypersurface. We prove that, given a complex number w, these hypersurfaces equidistribute towards the bifurcation current as n tends to infinity.Comment: Modified third section. Some results of Section 3 have been made more precise. Minor errors correcte

Algebraic Stochastic Calculus

We develop the foundations of Algebraic Stochastic Calculus, with an aim to replacing what is typically referred to as Stochastic Calculus by a purely categorical version thereof. We first give a sheaf theoretic reinterpretation of Probability Theory. We regard probability spaces (X, F, P) as Grothendieck sites (F, J_P) on which Brownian motions are defined via sheaves in symmetric monoidal infinity-categories. Due to the complex nature of such a formalism we are naturally led to considering a purely categorical, time independent formalism in which stochastic differential equations are replaced by studying problems in deformation theory.Comment: 21 page

Strong bifurcation loci of full Hausdorff dimension

In the moduli space $\mathcal{M}_d$ of degree $d$ rational maps, the bifurcation locus is the support of a closed $(1,1)$ positive current T_\bif which is called the bifurcation current. This current gives rise to a measure \mu_\bif:=(T_\bif)^{2d-2} whose support is the seat of strong bifurcations. Our main result says that \supp(\mu_\bif) has maximal Hausdorff dimension $2(2d-2)$. As a consequence, the set of degree $d$ rational maps having $2d-2$ distinct neutral cycles is dense in a set of full Hausdorff dimension.Comment: 37 page

Cross-national differences in the labour force attachment of mothers in Western and Eastern Europe

This paper examines cross-national differences in the labour force attachment of two specific subgroups of mothers: the stay-at-home mothers (homemakers) and those on maternity or parental leave. The justification for focusing on homemakers is that these women constitute an untapped source of labour and are among those who would need to join the labour market in order to reach the EU employment target. As to those on leave, their temporary absence from work means that they will soon be facing a time when they have to decide whether or not to return to the labour market. They are therefore also a key group to consider. In this paper, the characteristics and labour market intentions of these two subgroups of women are analysed using data from the Generations and Gender Survey (GGS) for ten countries: five Western European countries (Austria, Belgium, France, Germany and Italy), and five Eastern European countries (Bulgaria, Georgia, Lithuania, Romania and the Russian Federation). This paper is structured as follows. It first reviews the literature on women’s employment by focusing on both individual and macro-level factors, including values, education and family circumstances. It then moves on to a presentation of the data and methods, followed by the results of the data analysis. The paper concludes with a discussion of the results and their policy implications.