1,513 research outputs found
Evolution and dynamics of cusped light-like Wilson loops
We discuss the possible relation between the singular structure of TMDs on
the light-cone and the geometrical behaviour of rectangular Wilson loops.Comment: 6 pages, proceedings for the 3rd Workshop on the QCD Structure of the
Nucleon (QCD-N'12
Piecewise Linear Wilson lines
Wilson lines, being comparators that render non-local operator products gauge
invariant, are extensively used in QCD calculations, especially in small-
calculations, calculations concerning validation of factorisation schemes and
in calculations for constructing or modelling parton density functions. We
develop an algorithm to express piecewise path ordered exponentials as path
ordered integrals over the separate segments, and apply it on linear segments,
reducing the number of diagrams needed to be calculated. We show how different
linear path topologies can be related using their colour structure. This
framework allows one to easily switch results between different Wilson line
structures, which is especially useful when testing different structures
against each other, e.g. when checking universality properties of
non-perturbative objects.Comment: Proceedings for Transversity 2014, 6 page
Working With Wilson Lines
We present an algorithm to express Wilson lines that are defined on piecewise
linear paths in function of their individual segments, reducing the number of
diagrams needed to be calculated. The important step lies in the observation
that different linear path topologies can be related to each other using their
color structure. This framework allows one to easily switch results between
different Wilson line topologies, which is helpful when testing different
structures against each other.Comment: Proceedings for SPIN 2014, 6 page
A geometric study of marginally trapped surfaces in space forms and Robertson-Walker spacetimes -- an overview
A marginally trapped surface in a spacetime is a Riemannian surface whose
mean curvature vector is lightlike at every point. In this paper we give an
up-to-date overview of the differential geometric study of these surfaces in
Minkowski, de Sitter, anti-de Sitter and Robertson-Walker spacetimes. We give
the general local descriptions proven by Anciaux and his coworkers as well as
the known classifications of marginally trapped surfaces satisfying one of the
following additional geometric conditions: having positive relative nullity,
having parallel mean curvature vector field, having finite type Gauss map,
being invariant under a one-parameter group of ambient isometries, being
isotropic, being pseudo-umbilical. Finally, we provide examples of constant
Gaussian curvature marginally trapped surfaces and state some open questions.Comment: 21 page
- …