2025/06/29 by Silva, Edilberto O., Azevedo, Frankbelson dos S., Ahmed, Faizuddin · 3 citations
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)
paper · doi:10.48550/arxiv.2506.23291
We analyse a stationary, cylindrically symmetric spacetime endowed with an intrinsic helical twist, ds2 = -dt2 + dr2 + r2 dϕ2 + (dz + ω r dϕ)2. Solving the Einstein equations exactly yields an anisotropic energy-momentum tensor whose density is negative and decays as r-2, thus violating the weak energy condition near the axis. Three notable features emerge: (i) axis-centred negative energy; (ii) unequal transverse stresses; (iii) a torsional momentum flux Tϕzω3/r. We identify stable photon orbits and deflection angle, fully helical geodesics, and torsion-controlled wave optics modes, suggesting laboratory analogues in twisted liquid-crystal and photonic systems. The coupling between the torsion parameter ω and other physical parameters leads to significant effects, altering the motion along the positive or negative z-axis. These results make the twisted helical metric a useful test bed for studying the interplay of curvature, torsion, and matter in both gravitational and condensed-matter contexts.