(Trying again, emailer crashed.) E.Salamin:
From this reference http://www.aei.mpg.de/~schutz/download/lectures/AzoresCosmology/Schutz.Azore... the flux (power per unit area) carried by a gravitational wave of frequency f and strain s is
F = (pi/4) (c^3/G) f^2 s^2 WDS: 1. this formula cannot be right for large strains, at best it can be right only in the limit of small strains so can use linearized GR. Should be derivable from "stress-energy pseudotensor" https://en.wikipedia.org/wiki/Stress%E2%80%93energy%E2%80%93momentum_pseudot... 2. The contrast with Maxwell is interesting. Maxwell energy flux = ExB where E=electric & B=magnetic field, x=vector cross product note NO frequency dependence. 3. For a scalar field https://en.wikipedia.org/wiki/Stress%E2%80%93energy_tensor https://en.wikipedia.org/wiki/Scalar_field_solution again I see an f^2 frequency dependence. 4. So what is going on? Why for even-spin fields (gravity spin=2, scalar spin=0) do we have f^2 dependence while for odd-spin (Maxwell, photon spin=1) we have no frequency dependence? We get frequency f^n dependence if the stress energy tensor involves DERIVATIVES of the field, which in turn happens if the lagrangian density involves n field derivatives. For spin=0 & 2 we have n=2 (arising as squaring a first derivative). For spin=1 (Maxwell, Proca) we have n=0. The Dirac, Majorana, and Weyl (spin=1/2) fields all have n=1 according to http://arxiv.org/pdf/1006.1718.pdf so for them I would expect f^1 dependence. Rarita-Schwinger, which is one proposal for spin=3/2 fields, has n=1 according to https://en.wikipedia.org/wiki/Rarita%E2%80%93Schwinger_equation so for it also I would expect f^1 dependence. Is there some obvious unified reason these n had to happen in all these cases? -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)