Local vertex corrections from exchange-correlation kernels with a discontinuity

Beyond RPA Correlation Energies: Evaluation of Model Exchange-Correlation Kernels

The adiabatic-connection fluctuation-dissipation theorem (ACFDT) provides a formal frame work to treat the exchange-correlation energy. Under the random phase approximation (RPA), the effect of the exchange-correlation kernel is neglected, leading to the so-called EXX/RPA method. It has been shown that EXX/RPA yields overall a good description of structural properties of materials with differen...

The derivative discontinuity of the exchange-correlation functional.

The derivative discontinuity is a key concept in electronic structure theory in general and density functional theory in particular. The electronic energy of a quantum system exhibits derivative discontinuities with respect to different degrees of freedom that are a consequence of the integer nature of electrons. The classical understanding refers to the derivative discontinuity of the total en...

Discontinuity of the exchange-correlation potential from a density-functional viewpoint.

Correlation effects in a band ferromagnet: spin-rotationally-symmetric study with self-energy and vertex corrections

Quantum corrections to the transverse spin-fluctuation propagator are obtained by including self-energy and vertex corrections to first order within a spin-rotationallysymmetric inverse-degeneracy (1/N ) expansion scheme which preserves the Goldstone mode order by order. A correlation-induced exchange-energy correction is shown to yield the dominant quantum reduction in the spin stiffness, prov...

Constraining New Physics with Vertex Corrections

We discuss how new physics not encompassed within the STU oblique correction framework can be constrained from precision electroweak measurements via vertex corrections to Z–pole observables. 1. Limitations of the Oblique Correction Analysis In constructing models beyond the Standard Model (SM) such as technicolor or supersymmetric theories, it is important to test their viability by looking fo...