The paper finds infinite families of exotic spheres with free actions.
arXiv research
A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.
Trend · papers per month
Here we generalize the Gromoll-Meyer construction of an exotic 7-sphere by producing geometric models of exotic 8, 10 and Kervaire spheres as quotients of sphere bundles over spheres by free isometric actions. We give a geometric application at the end.
The (4k+2)-dimensional Kervaire manifold is a closed, piecewise linear (PL) manifold with Kervaire invariant 1 and the same homology as the product of two (2k+1)-dimensional spheres. We show that a finite group of odd order acts freely on a Kervaire manifold if and only if it acts freely on the corresponding product of…
This paper extends widely the work in \cite{GT13}. Existence and non-existence results of isoparametric functions on exotic spheres and Eells-Kuiper projective planes are established. In particular, every homotopy -sphere () carries an isoparametric function (with certain metric) with 2 points as the focal set,…
In contrast to the homogeneous case, we show that there are compact cohomogeneity one manifolds, that do not support invariant metrics of non-negative sectional curvature. In fact we exhibit infinite families of such manifolds including the exotic Kervaire spheres. Such examples exist for any codimension of the singula…
Study of Morse functions with constraints and their bordism groups.
New metrics found on manifolds using Cheeger deformations.
Classical Delaunay surfaces are highly symmetric constant mean curvature (CMC) submanifolds of space forms. We prove the existence of Delaunay-type hypersurfaces in a large class of compact manifolds, using the geometry of cohomogeneity one group actions and variational bifurcation techniques. Our construction speciali…
Completes classification of high-dimensional manifolds up to exotic sums.
Kervaire's sphere-link is equivalent to a ribbon sphere-link, simplifying complex 2-complexes.
Study detects Hopf elements and Kervaire classes in sphere spectra.
It is proved that there exists an integer such that a framed manifold of dimension , has the trivial Kervaire Invariant.
We show that Kervaire invariant one elements in the homotopy groups of spheres exist only in dimensions at most 126. By Browder's Theorem, this means that smooth framed manifolds of Kervaire invariant one exist only in dimensions 2, 6, 14, 30, 62, and possibly 126. With the exception of dimension 126 this resolves a lo…
Proves surface embedding theorem for 4-manifolds with good fundamental group.
The paper explores smooth equivariant rigidity and finds infinitely many exotic smooth structures.
New actions found on exotic spheres using group theory.
The first part of the paper is to improve the fundamental theory of isoparametric functions on general Riemannian manifolds. Next we focus our attention on exotic spheres, especially on "exotic" 4-spheres (if exist) and the Gromoll-Meyer sphere. In particular, as one of main results we prove: there exists no properly t…
Study shows exotic Dehn twists on certain 3-sphere fillings.
The study proves conditions for embedding manifolds into complex spaces.
A physicist explores exotic 7-spheres using fibre bundles and instantons.
Study compares characteristic classes of bundles with exotic spheres.
Detects exotic embeddings in 4-manifolds with boundary.
New tools prove smooth actions on exotic spheres.
Proves existence of manifolds with Kervaire invariant one in specific dimensions.
We construct a new infinite family of models of exotic 7-spheres. These models are direct generalizations of the Gromoll-Meyer sphere. From their symmetries, geodesics and submanifolds half of them are closer to the standard 7-sphere than any other known model for an exotic 7-sphere.
Paper constructs exotic spacetimes with same physical properties.
Study finds infinite families of Sasaki-Einstein metrics on spheres.
Extends exotic embeddings of RP^2 to a larger family and produces homotopy spheres.
We prove the existence of exotic but homotopically trivial contact structures on spheres of dimension 8k-1. Together with previous results of Eliashberg and the second author this establishes the existence of such structures on all odd-dimensional spheres (of dimension at least 3).
Exotic submanifolds in 4-manifolds remain exotic after stabilizations.
In dimensions congruent to 1 modulo 4, we prove that the cotangent bundle of an exotic sphere which does not bound a parallelisable manifold is not symplectomorphic to the cotangent bundle of the standard sphere. More precisely, we prove that such an exotic sphere cannot embed as a Lagrangian in the cotangent bundle of…
We present Michel Kervaire work on knots in higher dimensions.
We prove the existence of an abundance of new Einstein metrics on odd dimensional spheres including exotic spheres, many of them depending on continuous parameters. The number of families as well as the number of parameter grows double exponentially with the dimension. Our method of proof uses Brieskorn-Pham singularit…
Detecting exotic spheres involves analyzing framed configuration spaces.
Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. In the second paper, we calculate the "smoothness structure" part of the path integral in quantum gravity for the exotic R^4 as non-compact manifold. We discuss the influence of th…
Study on stochastic flows on 7-dimensional spheres.
Study finite group actions on exotic aspherical space forms.
We present an infinite sequence of smooth embeddings of a connected sum of 6 projective planes in the 4-sphere, which are all ambient homeomorphic, but pairwise ambient non-diffeomorphic. The double covers of the 4-sphere ramified along these surfaces form a family of the exotic $\Bbb CP^2#5\bar{\Bbb CP^2}$ constructed…
The paper explores holographic structures on exotic spheres and their implications.
We construct Anosov diffeomorphisms on manifolds that are homeomorphic to infranilmanifolds yet have exotic smooth structures. These manifolds are obtained from standard infranilmanifolds by connected summing with certain exotic spheres. Our construction produces Anosov diffeomorphisms of high codimension on infranilma…
New method classifies spin 4-manifolds using Kervaire-Milnor invariant.
New methods distinguish exotic 4-manifolds using Heegaard Floer homology.
New results on localization of exotic diffeomorphisms in 4-manifolds.
Study on stochastic flows on exotic spheres, exploring their properties.
Study on curvature properties of exotic 7-sphere using quaternionic geometry.
A metric with positive sectional curvature on the Gromoll-Meyer exotic 7-sphere is constructed explicitly. The proof relies on a 2-parameter family of left invariant metrics on Sp(2) and a one-parameter family of conformal deformations via an isoparametric function F on it. One byproduct is a metric with positive secti…
We construct a co-dimension completely non-holonomic sub-bundle on the Gromoll-Meyer exotic sphere based on its realization as a base space of a Sp(2)-principal bundle with the structure group Sp(1). The same method is valid for constructing a co-dimension 3 completely non-holonomic sub-bundle on the standard 7…
We show that there is a metric on the Gromoll-Meyer sphere with positive sectional curvature.