Exact Spinning Morris-Thorne Wormhole: Causal Structure, Shadows, and Multipole Moments

Abstract

We construct an exact spinning generalisation of the Morris-Thorne traversable wormhole supported by an anisotropic fluid. Within the Teo wormhole ansatz with unit lapse and Morris-Thorne shape function, we solve analytically for the frame-dragging function and obtain a two-parameter family of asymptotically flat solutions labelled by the throat radius $r_0$ and total angular momentum $J$. Curvature scalars and stress-energy components are given in closed form, showing a regular throat, equatorial reflection symmetry, and violations of all standard energy conditions, as required for traversable wormholes. We analyse the causal structure and show that, despite the presence of an ergoregion for sufficiently large $|J|$, the coordinate time defines a global temporal function, so the spacetime is stably causal and free of closed timelike curves. The optical appearance is studied via photon trajectories. The resulting shadows are smaller than Kerr's and depend on the wormhole shape. Finally, we compute the Geroch-Hansen multipole moments and find a massless but spinning configuration with distinctive higher multipoles that encode the throat scale.

16 pages, 2 figures

References in corpus (17)

• Stationary Black Holes: Uniqueness and Beyond
• Rotating traversable wormholes
• The Shadow of a Rotating Traversable Wormhole
• Shadows of rotating wormholes
• Rotating Ellis Wormholes in Four Dimensions
• Corrections and Comments on the Multipole Moments of Axisymmetric Electrovacuum Spacetimes
• Slowly rotating scalar field wormholes: the second order approximation
• Axially symmetric rotating traversable wormholes
• Rotating wormhole solutions with a complex phantom scalar field
• Quasi-periodic oscillations from the accretion disk around rotating traversable wormholes
• Quasi-periodic Oscillations in Rotating Ellis Wormhole Spacetimes
• Exact rotating wormholes via Ehlers transformations
• Symmetric and Asymmetric Wormholes Immersed In Rotating Matter
• Rotating traversable wormholes in Einstein-Maxwell theory
• Gravitational Multipoles in General Stationary Spacetimes
• Are slowly rotating Ellis-Bronnikov wormholes stable?
• Rotating traversable wormhole geometries in the presence of three-form fields

Cited by in corpus (1)

• An exact Kerr-like rotating Morris--Thorne wormhole: throat, ergoregion and equatorial shadow slice