Seminars
A Particle with Torsion in Mielke--Baekler Spacetimes. Teleparallel ideas in 2+1 dimensions at work.
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Description
Abstract:
The Mielke--Baekler spacetimes are three-dimensional
reductive homogeneous spaces together with a choice of invariant
connection which is compatible with a lorentzian metric. The
spacetimes generalise Minkowski and (anti)de~Sitter spacetimes in
that the invariant metric connection can have torsion, a peculiarity
of three dimensions. Using the techniques of nonlinear
realisations, we construct worldline actions for massive spinning
particles moving in these spacetimes. We pay particular attention to
the so-called teleparallel branch, in which the curvature vanishes.
We show in this case that the
spinning particle trajectories are geodesic relative to a
Weitzenböck connection or, equivalently, as a Papapetrou-type
equation with a spin-curvature force in the Levi-Civita
description. We also present the canonical action and discuss the
resulting physical degrees of freedom. We then take the carrollian
limit of these geometries and introduce the carrollian analogues of
the Mielke--Baekler spacetimes and repeat the analysis in that
case.
reductive homogeneous spaces together with a choice of invariant
connection which is compatible with a lorentzian metric. The
spacetimes generalise Minkowski and (anti)de~Sitter spacetimes in
that the invariant metric connection can have torsion, a peculiarity
of three dimensions. Using the techniques of nonlinear
realisations, we construct worldline actions for massive spinning
particles moving in these spacetimes. We pay particular attention to
the so-called teleparallel branch, in which the curvature vanishes.
We show in this case that the
spinning particle trajectories are geodesic relative to a
Weitzenböck connection or, equivalently, as a Papapetrou-type
equation with a spin-curvature force in the Levi-Civita
description. We also present the canonical action and discuss the
resulting physical degrees of freedom. We then take the carrollian
limit of these geometries and introduce the carrollian analogues of
the Mielke--Baekler spacetimes and repeat the analysis in that
case.