On Nonlinear Shell Theories

On-Shell Recursion Relations for Generic Theories

We show that on-shell recursion relations hold for tree amplitudes in generic two derivative theories of multiple particle species and diverse spins. For example, in a gauge theory coupled to scalars and fermions, any amplitude with at least one gluon obeys a recursion relation. In (super)gravity coupled to scalars and fermions, the same holds for any amplitude with at least one graviton. This ...

On-Shell Recursion Relations for Effective Field Theories.

We derive the first ever on-shell recursion relations applicable to effective field theories. Based solely on factorization and the soft behavior of amplitudes, these recursion relations employ a new rescaling momentum shift to construct all tree-level scattering amplitudes in the nonlinear sigma model, Dirac-Born-Infeld theory, and the Galileon. Our results prove that all theories with enhance...

Incompressibility in rod and shell theories

We treat the problem of constructmg exact théories of rods and shells for thm mcom pressible bodies We employ a systematic method that consists m imposmg constramts to reduce the number of degrees of freedom df each cross section to a finit e number We show that it is very difficult to produce théories that exactly preserve the mcompressibihty and we show that it is impossible to do so for naïv...

Nonlinear Wave Theories

On the nonlinear KK reductions on spheres of supergravity theories

We address some issues related to the construction of general KaluzaKlein (KK) ansätze for the compactification of a supergravity (sugra) theory on a sphere Sm. We first reproduce various ansätze for compactification to 7d from the ansatz for the full nonlinear KK reduction of 11d sugra on AdS7×S4. As a side result, we obtain a lagrangean formulation of 7d N = 2 gauged sugra, which so far had o...