Search arXiv⌕ Search

arXiv · hep-th/9903260

A Note on Higher Dimensional Instantons and Supersymmetric Cycles

Abstract

We discuss instantons in dimensions higher than four. A generalized self-dual or anti-self-dual instanton equation in n-dimensions can be defined in terms of a closed (n-4) form $Ω$ and it was recently employed as a topological gauge fixing condition in higher dimensional generalizations of cohomological Yang-Mills theory. When $Ω$ is a calibration which is naturally introduced on the manifold of special holomony, we argue that higher dimensional instanton may be locally characterized as a family of four dimensional instantons over a supersymmetric (n-4) cycle $Σ$ with respect to the calibration $Ω$. This is an instanton configuration on the total space of the normal bundle $N(Σ)$ of the submanifold $Σ$ and regarded as a natural generalization of point-like instanton in four dimensions that plays a distinguished role in a compactification of instanton moduli space.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

H. Kanno. 1999-04-01. A Note on Higher Dimensional Instantons and Supersymmetric Cycles. https://doi.org/10.1143/ptps.135.18

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Euler-Heisenberg actions in higher dimensions

Using Schwinger's proper-time formalism, we compute the one-loop effective action in both spinor and scalar quantum electrodynamics in $d=2n>4$ dimensions using algebraic techniques. We derive the closed form expression for the corresponding Euler-Heisenberg Lagrangian, and extract its weak-field approximation in 6, 8 and 10 dimensions in terms of invariants of the electromagnetic field. A subsequent analysis of pair production in $d$ dimensions is given. We also elaborate on conformal actions for the electromagnetic field in $d=2n>4$ dimensions. In the $d=6$ and 8 cases, such actions are generated by DeWitt's coefficients $a_3$ and $a_4$ which, for completeness, are re-computed in this work for spinor QED and scalar QED, respectively.

hep-th↗

Finite-time memory detectors and fully constraining Faddeev-Kulish dressings in QED and gravity

We show that for both QED and perturbative quantum gravity, time dependent Faddeev-Kulish dressings can be fully constrained either by symmetry, or by demanding that they reproduce the correct outgoing classical memory contribution. For gravity, we show that using this dressing to construct finite-time Fock spaces allows us to recover both the first order gravitational memory, as well as higher order Christodoulou contributions from the gravitational field. We explain how these higher order perturbative corrections arise in inclusive in-in calculations.

hep-th↗

Effect of $ξRϕ^2$ non-minimal coupling on gravitational light bending

We investigate the bending of massless fields by a massive object in the presence of a curvature-scalar $\sqrt{-g}ξR ϕ^2$ non-minimal coupling up to one loop, using the perturbative quantum gravity computations. It is well known that without such coupling a self interacting scalar field theory cannot be renormalised in the presence of gravity. The massive object is modelled by a massive scalar $ϕ$, and it is assumed to be non-relativistic, e.g., a star. We compute the 2-2 scattering of massless scalar and photons off this object via graviton exchanges. Assuming both $ξ$ and the bending angle to be small, we use the eikonal approximation to compute the angle up to ${\cal O}(ξG^2)$. At tree level $({\cal O}(ξG))$ we find no bending, and hence the ${\cal O}(ξG^2)$ result happens to be leading in this case. The non-minimal vertices are qualitatively different from that of the standard minimal ones, e.g. $ \sqrt{G} h_{μν} T^{μν}$, as the former contains explicit momenta of the gravitons instead of the scalar, complementing the second. The bending angle is found to behave like $\sim b^{-7}$, where $b$ is the impact parameter. We have emphasised the qualitative differences of our results from that of the well studied minimal case.

hep-th↗