47 research outputs found
Rigidity and defect actions in Landau-Ginzburg models
Studying two-dimensional field theories in the presence of defect lines
naturally gives rise to monoidal categories: their objects are the different
(topological) defect conditions, their morphisms are junction fields, and their
tensor product describes the fusion of defects. These categories should be
equipped with a duality operation corresponding to reversing the orientation of
the defect line, providing a rigid and pivotal structure. We make this
structure explicit in topological Landau-Ginzburg models with potential x^d,
where defects are described by matrix factorisations of x^d-y^d. The duality
allows to compute an action of defects on bulk fields, which we compare to the
corresponding N=2 conformal field theories. We find that the two actions differ
by phases.Comment: 53 pages; v2: clarified exposition of pivotal structures, corrected
proof of theorem 2.13, added remark 3.9; version to appear in CM
Homological Mirror Symmetry for Calabi-Yau hypersurfaces in projective space
We prove Homological Mirror Symmetry for a smooth d-dimensional Calabi-Yau
hypersurface in projective space, for any d > 2 (for example, d = 3 is the
quintic three-fold). The main techniques involved in the proof are: the
construction of an immersed Lagrangian sphere in the `d-dimensional pair of
pants'; the introduction of the `relative Fukaya category', and an
understanding of its grading structure; a description of the behaviour of this
category with respect to branched covers (via an `orbifold' Fukaya category); a
Morse-Bott model for the relative Fukaya category that allows one to make
explicit computations; and the introduction of certain graded categories of
matrix factorizations mirror to the relative Fukaya category.Comment: 133 pages, 17 figures. Changes to the argument ruling out sphere
bubbling in the relative Fukaya category, and dealing with the behaviour of
the symplectic form under branched covers. Other minor changes suggested by
the referee. List of notation include
Women on boards of Malaysian firms: Impact on market and accounting performance
We seek to offer some reconciliation for the conflicting theoretical arguments and empirical findings regarding the impact of women’s participation in boards on firms’ performance.We suggest that this impact differs in relation to market- and accounting-performance, and it is firm-specific, and varies by firms’ ownership type and the composition of their boards.These arguments find theoretical underpinnings in agency and resource-dependency theories, combined with behavioral and discrimination theories that articulate women behavior in the workplace and market perception of gender equality.The empirical analysis is based on a dataset of 841 publicly-listed firms in Malaysia.The results show positive impact of women’s participation on accounting-performance and negative impact on market-performance, suggesting that women directors create economic value, which is undervalued by the market. We interpret the findings with reference to the perception of women’s role in society and business in Malaysia, and the nature of corporate governance and ownership types prevalent among Malaysian firms.We suggest that the relationships might be context-specific, and hence the desired level of women’s participation varies across countries.We discuss the normative implications of the findings for government authorities considering legislation of gender-quota on boards, and for firms