I would like to make a conjecture. It says: every elementary particle in the Standard Model (except the Higgs) of spin s has a dual partner of spin 1/s.
So the fermions (spin 1/2) in the Standard Model would have spin 2 dual partners and the bosons (spin 1) in the Standard Model would be their own dual.
Of course, for this to work we need to have at least one spin 2 particle. Maybe many more. So gravity appears automatically.
Content written and posted by Ken Abbott abbottsystems@gmail.com