Search arXiv⌕ Search

arXiv · math/9812042

Four-manifold geography and superconformal symmetry

Abstract

A compact oriented 4-manifold is defined to be of ``superconformal simple type'' if certain polynomials in the basic classes (constructed using the Seiberg-Witten invariants) vanish identically. We show that all known 4-manifolds of $b_2^+>1$ are of superconformal simple type, and that the numerical invariants of 4-manifolds of superconformal simple type satisfy a generalization of the Noether inequality. We sketch how these phenomena are predicted by the existence of certain four-dimensional superconformal quantum field theories.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Marcos Marino, Gregory Moore, Grigor Peradze. 1998-12-09. Four-manifold geography and superconformal symmetry. https://arxiv.org/abs/math/9812042

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

KEEP EXPLORING

Related papers

Shrinkers of the area-preserving curve-shortening flow: Classification and saddle-point property

We consider homothetic evolutions of the area-preserving curve-shortening flow (APCSF), that is, classical curve-shortening flow with an additional non-local forcing term. By using known results on $λ$-curves, we prove the existence of non-circular shrinkers for this flow. In our first main result, we present a full classification of such curves, similar to the well-known Abresch-Langer classification for shrinkers of curve-shortening flow. Finally, we also deduce a saddle-point property for all non-circular (APCSF)-shrinkers analogous to the known saddle-point property of Abresch-Langer curves.

math.DG↗

A non-trivial index difference on surfaces of genus at least $3$

For every closed surface of genus at least $3$, equipped with any bounding spin structure, we show that the index difference, viewed as a map from the fundamental group of the space of Dirac-invertible Riemannian metrics to $\KO^{-4}(*)$, is non-trivial. If the genus is at least $5$, we also show that the aforementioned index difference is surjective. For products of two closed surfaces of genus at least $3$, equipped with any spin structure, we prove that the corresponding space of Dirac-invertible Riemannian metrics is not contractible. We discuss the relationship of this result to the existence of metrics with harmonic spinors in dimension~$4$.

math.DG↗

A sharp mass-volume inequality on Einstein manifolds and ADM mass

Let $(M^n,g), n\geq 4$ be a close Einstein manifold with positive scalar curvature and $G$ be the Green function of the conformal Laplacian. The ADM mass of the asymptotically flat metric $\hat g:=G^{4/(n-2)} g$ is an important geometric invariant. When either $n=5$ or $n\geq 6$ with Weyl vanishing condition, we prove a mass formula, generalizing Gursky-Malchiodi's formula in dimension $4$. An important step is an extension of Viaclovsky's Green function expansion in higher dimensions. Next we prove a sharp inequality related to the volume radius and the mass for Einstein manifolds. Finally we present two applications. First, we prove a mass gap theorem for Einstein manifolds. Second, for a volume collapsing family of normalized Einstein $n$-manifolds $(M_i,g_i)$ (satisfying the Weyl vanishing condition when $n\geq 6$), we prove that the mass sequence $m(\widehat{g_i})$ blows up uniformly as $i\to\infty$. This in particular applies to Collins-Székelyhidi's family of Sasaki-Einstein metrics $g_i$ on $\mathbb{S}^5$, and to the recent $4$-dimensional examples of T. Ozuch.

math.DG↗