Is there any general theorem which specifies conditions where the critical solution of an action is unique (for given boundary conditions)?
66919
When/why does the principle of least action plus boundary conditions not uniquely specify a path?
153580
Solutions of autonomous ODEs are monotonic
72721
Do an action and its Euler-Lagrange equations have the same symmetries?
74452
On a uniqueness proof for solutions of $\ a + x = b\,$ in a group
122390
Is every solution of Einstein field equations unique?
137451
Does there exist a differentiable conservative vector field with non - vanishing curl?
13644
Is the change in the Lagrangian always a total derivative for symmetry transformations of the action?
157960
How can I prove the existence of two values in a given domain Mean value theorem?
140009
Show complex solutions exist
108118
Poincaré-Bendixon show periodic solutions.
64228
D'Alemberts Principle to solve a Classical Mechanics problem
71479
Is there some elementary proof of invariance of domain?
133471
Solve a PDE on a domain $\Omega$ with given boundary conditions
149737
For which values does the Matrix system have a unique solution, infinitely many solutions and no solution?
70734
Entropy and the principle of least action
115224
Equivalences of $\diamondsuit$-principle.
39321
If $f:\mathbb R \to \mathbb R$ satisfies $f'(x) <L$ for some $L<1$, then $f$ has a unique fixed point