Perturbation

A general density perturbation is a mixture of both, and different theories that purport to explain the primordial density perturbation spectrum predict different mixtures.

He then solved the same problem by treating the anharmonic potential term as a perturbation to the harmonic oscillator and using the perturbation methods that he and Born had developed.

Cloud brightening yields a much greater impact on the weather for a much smaller perturbation than directly cooling the ocean, he explained.

That slight perturbation was magnified exponentially when eight hours later two other associates had texted me at 8:03 am and 8:30 am, respectively, with questions and well wishes that honestly I couldn’t receive, nor respond to at that hour.

As the perturbation increases and the smooth curves disintegrate we move from KAM theory to Aubry-Mather theory which requires less stringent hypotheses and works with the Cantor-like sets.

Becker, Becker, and Schwarz 2007, p. 2 The interaction of strings is most straightforwardly defined by generalizing the perturbation theory used in ordinary quantum field theory.

Centaurs are not in stable orbits and will be removed by gravitational perturbation by the giant planets over a period of millions of years, moving to different orbits or leaving the Solar System altogether.

David Gross and Vipul Periwal discovered that string perturbation theory was divergent.

Dyson could show that a rescaling of charge and mass (‘renormalization’) is sufficient to remove all divergences in QED to all orders of perturbation theory.

Even so, the total perturbation does not coincide with experiment, and an empirical spin orbit coupling must be added with at least two or three different values of its coupling constant, depending on the nuclei being studied.

However, microfossils such as stromatolites and oncolites prove that, in shallow marine environments at least, life did not suffer any perturbation.

However, perturbation theory (and with it the concept of a "force-mediating particle") fails in other situations.

However, the terms are normally used to refer to objects free from significant perturbation from Neptune, thereby excluding KBOs in orbital resonance with Neptune ( resonant trans-Neptunian objects ).

If the perturbation required is small, on the order of the uncertainty in the input data, then the results are in some sense as accurate as the data "deserves".

If there are not, then "stability" asks whether a small perturbation will grow, oscillate, or be damped out.

Indeed, such second-order and higher-order perturbation calculations can give apparently infinite contributions to the sum.

In some cases, a PDE can be solved via perturbation analysis in which the solution is considered to be a correction to an equation with a known solution.

In this case, to a very high approximation : that is, there is no probability for a transition, and the system is in the initial state after cessation of the perturbation.

Objects must orbit Earth within this radius, or they can become unbound by the gravitational perturbation of the Sun.

One such effective field theory is chiral perturbation theory or ChiPT, which is the QCD effective theory at low energies.