Gauge theories of gravity & energetics

Gauge theories can be constructed which describe gravitation as a Lagrangian field theory on Minkowski space. Notably, Gauge Theory Gravity (GTG) is the spin-torsion theory that follows from demanding local displacement and rotational invariance. GTG is cast in the unifying mathematical language of geometric algebra, which is well adapted to the gauge theory approach. Currently an `extended Weyl Gauge Theory' (eWGT) is under development which additionally accommodates local scale invariance. Areas of research are solutions to the field equations and their cosmological implications, including possible dark matter/energy effects, and the effects of spin as a gravitational source. We will also study the `gravitational energy problem' and definitions of mass in these theories.