Discussion Overview
The discussion revolves around the role of torsion in string theory, particularly in relation to general relativity and its implications for theories involving fermions and supergravity. Participants explore the theoretical significance of torsion and its potential consequences in string theory.
Discussion Character
- Exploratory
- Debate/contested
- Technical explanation
Main Points Raised
- Some participants note that general relativity assumes a torsion-free connection, but argue that torsion should not be ignored from a geometrical perspective, especially in string theory.
- One participant suggests that in gravity coupled to spinors, torsion should be considered, proposing that fermionic superstrings might have a non-zero spinor tensor.
- Another participant expresses a preference for the Einstein-Cartan theory, which incorporates non-vanishing torsion, and argues that this framework is more natural than pure general relativity.
- A participant mentions "discrete torsion" in string theory, referencing its origins in the context of orbifolds and questioning its relationship to torsion in Einstein-Cartan theory.
- One participant expresses uncertainty about the relevance of torsion in string theory, suggesting that since string theory produces the equations of general relativity, torsion may not be applicable.
- Another participant agrees that string theory produces supergravity, indicating that there is no inherent reason to restrict it to a torsion-free framework.
Areas of Agreement / Disagreement
Participants express differing views on the relevance and implications of torsion in string theory. While some argue for its significance, others question its applicability, leading to an unresolved discussion regarding its role.
Contextual Notes
Participants acknowledge that torsion is non-propagating and may vanish in the vacuum, which complicates its detection and relevance in practical scenarios.