Singular lensing from the scattering on special space-time defects.

Area of Science:

• Theoretical Physics
• General Relativity
• Particle Physics

Background:

• Self-gravitating point-like defects, like global monopoles, create non-asymptotically flat spacetimes with solid angle deficits.
• Particle scattering in these spacetimes can lead to resonant behavior and 'singular lensing' due to divergent cross-sections.
• Renewed interest in defect theory necessitates a re-examination of these phenomena and their computational subtleties.

Purpose of the Study:

• To contextualize singular lensing within contemporary theoretical physics and defect phenomenology.
• To address computational subtleties in calculating singular lensing effects.
• To ensure the validity of theoretical frameworks, including the optical theorem, in the context of these spacetimes.

Main Methods:

• Employed a specific regularization procedure for infinite Legendre series encountered in scattering amplitude calculations.
• Utilized an alternative calculation method exploiting asymptotic properties of Fresnel integrals.
• Compared results with the traditional approach using the generating function of Legendre polynomials.

Main Results:

• Successfully recovered Minkowski spacetime in the no-defect limit, eliminating the lensing phenomenon.
• Confirmed the validity of the optical theorem for the elastic total cross-section.
• The alternative calculation method corroborated the singular nature of the lensing phenomenon.

Conclusions:

• The study provides a more robust understanding of singular lensing caused by self-gravitating defects.
• The adopted regularization procedure resolves previous computational issues and ensures physical consistency.
• The findings contribute to the broader understanding of particle interactions in exotic spacetimes.