A class of colliding waves in metric-affine gravity, nonmetricity and torsion shock waves (Q2738192)

The most general electrovacuum class of colliding waves with fourth degree polynomials in the framework of metric-affine gravity is found and expressed in the advanced and retarded time coordinates. It is assumed that two noncollinear polarized gravitational plane waves possessing five symmetries approach each other from opposite sides in flat Minkowski background. After the collision a new gravitational field with torsion and nonmetricity develops and the resulting geometry has cylindrical symmetry. Solutions of the general fourth degree polynomials can be reduced to the well known second degree polynomials cases which enables the interpretation of the resulting waves as curvature, nonmetricity, and torsion shock waves.