Constraints from Consistency: Implications for a Massive Spin-$3/2$ Field
by
Prof.Diptimoy Ghosh(IISER Pune)
→
Asia/Kolkata
A304 and on Zoom
A304 and on Zoom
Description
Consistency principles—relativity, quantum mechanics, unitarity, and analyticity—place strong constraints on how particle interactions can be organized. Rather than allowing arbitrary possibilities, these basic requirements significantly narrow the space of viable theories and often enforce nontrivial relations among seemingly independent couplings.
Focusing on a massive spin-$3/2$ field, these constraints become particularly restrictive. Using dispersive bounds on non-forward $2 \to 2$ scattering amplitudes, the allowed space of effective couplings can be mapped explicitly. For masses well below the Planck scale, this space forms a bounded region whose boundary includes the supergravity point, with a volume that shrinks parametrically as $(m/M_{\rm Pl})^6$ and vanishes smoothly in the massless limit.
This provides a concrete setting in which general consistency conditions sharply constrain the structure of the low-energy theory.