View example sentences and word forms for Perturbative.
Perturbative meaning
Of, pertaining to, or causing perturbation
Example sentences (14)
In the perturbative approach to quantum field theory, the full field interaction terms are approximated as a perturbative expansion in the number of particles involved.
A graviton in perturbative string theory is a closed string in a very particular low-energy vibrational state.
Becker, Becker, and Schwarz 2007, p. 6 Unlike in quantum field theory, string theory does not have a full non-perturbative definition, so many of the theoretical questions that physicists would like to answer remain out of reach.
Developed by Richard Feynman and others in the first half of the twentieth century, perturbative quantum field theory uses special diagrams called Feynman diagrams to organize computations.
Holography allowed them to conclude that the dynamics of these black holes give a complete non-perturbative formulation of M-theory.
It is only because non-perturbative effects appear in hidden form in diagrams that it was possible to analyze nonperturbative effects in string theory, where in many cases a Feynman description is the only one available.
More precisely, one cannot apply the methods of perturbative quantum field theory.
Notably, it has been extended to non-Hamiltonian systems (starting with Moser), to non-perturbative situations (as in the work of Michael Herman ) and to systems with fast and slow frequencies (as in the work of Mikhail B. Sevryuk).
Other non-perturbative tests are currently at the level of 5% at best.
Renormalization Early in the history of quantum field theory, it was found that many seemingly innocuous calculations, such as the perturbative shift in the energy of an electron due to the presence of the electromagnetic field, give infinite results.
Stephen Shenker showed it diverged much faster than in field theory suggesting that new non-perturbative objects were missing.
These were understood to be the new objects suggested by the perturbative divergences, and they opened up a new field with rich mathematical structure.
Thus a perturbative element of work has been done without heat transfer and without introduction of random change within the system.
When calculating the fluctuations with a perturbative approach, the zero order approximation is Fick's law.