What is "perturbative"

Usage examples of "perturbative".

If we tried to use a perturbative approach by, say, singling out the gravitational attraction between two stars and using it to determine our ballpark approximation, we would quickly find that our approach had failed.

As we now discuss, these issues are particularly crucial for applying perturbative tools to physical processes in the microworld.

Instead, string theorists have cast these calculations into a perturbative framework based on the expectation that a reasonable ballpark estimate is given by the zero-loop processes, with the loop diagrams resulting in refinements that get smaller as the number of loops increases.

This is just what is needed for the perturbative framework, since it indicates that we will get reasonably accurate results even if we ignore all processes except for those with just a few loops.

As in the case of a trinary star system, this invalidates a perturbative approach.

We can be sure that conclusions based on a perturbative framework are justified only if the string coupling constant is less than 1.

Currently, however, physicists have been able to find only an approximation to this equation, in each of the five string theories, by mathematically evaluating a small number of relevant string diagrams using a perturbative approach.

We are attempting to use a perturbative approach to determine the value of the string coupling constant itself.

Inspired by earlier works of Duff, Hull, Townsend, and building on insights of Schwarz, the Indian physicist Ashok Sen, and others, Witten announced a strategy for transcending the perturbative understanding of string theory.

The calculation of these properties, which necessarily transcends the perturbative framework, has played a central role in driving the progress of the second superstring revolution and is firmly rooted in the power of symmetry.

BPS states is that their properties are uniquely, easily, and exactly determined without resort to a perturbative calculation.

That is, even if the string coupling constant is large, implying that the perturbative approach is invalid, we are still able to deduce the exact properties of the BPS configurations.

In this case, perturbative tools are valid, and hence many of the detailed properties of the theory can and have been worked out with accuracy.

If we increase the value of the coupling constant but still keep it a good deal less than 1, perturbative methods can still be used.

But beyond these changes in detailed numerical properties, the overall physical content of the theory remains the same, so long as the coupling constant stays in the perturbative realm.