All Questions
3 questions
2
votes
0
answers
61
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Ostrogradsky instability and fractional derivatives
Are fractional derivatives (or even more generally differentegrals) also under the scope of the Ostrogradsky instability theorem?
3
votes
0
answers
68
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Lattice differentiation and Locality
Assume we define the locality of a theory in the following way:
Assume we have a theory of real scalars, so this theory is non local if the action has terms like
$$\int d^dx\,\phi(x)V(x-y)\phi(y).$$
...
3
votes
3
answers
578
views
Infinite derivatives, Locality and Lagrangian
Providing the derivative of a single valued function $f(x)$ is like providing its value at two infinitesimally close points.
My question consists of two parts:
Can Higher derivatives be thought of as ...