Has anyone described 'unfolding' as used in mathematical physics (e.g. on-shell AND off-shell) as analogous to a resolution in algebra - higher derivatives are unfolded in terms of new variables?

Hi Jim, do you have a reference where this term is used and applied? Is it a vague general procedure or is it reasonably well defined (for mathematical physics, that is)?
– David RobertsJun 15 '12 at 22:45

I believe he is referring the the procedure by which you expand a higher-order differential equation as a first order equation in more variables, by introducing new variables like "$k$th derivative of $x$".
– S. Carnahan♦Jun 16 '12 at 10:56