574 research outputs found

    The triviality of the 61-stem in the stable homotopy groups of spheres

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    We prove that the 2-primary π61\pi_{61} is zero. As a consequence, the Kervaire invariant element θ5\theta_5 is contained in the strictly defined 4-fold Toda bracket ⟨2,θ4,θ4,2⟩\langle 2, \theta_4, \theta_4, 2\rangle. Our result has a geometric corollary: the 61-sphere has a unique smooth structure and it is the last odd dimensional case - the only ones are S1,S3,S5S^1, S^3, S^5 and S61S^{61}. Our proof is a computation of homotopy groups of spheres. A major part of this paper is to prove an Adams differential d3(D3)=B3d_3(D_3) = B_3. We prove this differential by introducing a new technique based on the algebraic and geometric Kahn-Priddy theorems. The success of this technique suggests a theoretical way to prove Adams differentials in the sphere spectrum inductively by use of differentials in truncated projective spectra.Comment: 67 pages, minor changes, accepted versio

    The special fiber of the motivic deformation of the stable homotopy category is algebraic

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    For each prime pp, we define a tt-structure on the category S0,0^/τ-Modharmb\widehat{S^{0,0}}/\tau\text{-}\mathbf{Mod}_{harm}^b of harmonic C\mathbb{C}-motivic left module spectra over S0,0^/τ\widehat{S^{0,0}}/\tau, whose MGL-homology has bounded Chow-Novikov degree, such that its heart is equivalent to the abelian category of pp-completed BP∗BPBP_*BP-comodules that are concentrated in even degrees. We prove that S0,0^/τ-Modharmb\widehat{S^{0,0}}/\tau\text{-}\mathbf{Mod}_{harm}^b is equivalent to Db(BP∗BP-Comodev)\mathcal{D}^b({{BP}_*{BP}\text{-}\mathbf{Comod}}^{{ev}}) as stable ∞\infty-categories equipped with tt-structures. As an application, for each prime pp, we prove that the motivic Adams spectral sequence for S0,0^/τ\widehat{S^{0,0}}/\tau, which converges to the motivic homotopy groups of S0,0^/τ\widehat{S^{0,0}}/\tau, is isomorphic to the algebraic Novikov spectral sequence, which converges to the classical Adams-Novikov E2E_2-page for the sphere spectrum S0^\widehat{S^0}. This isomorphism of spectral sequences allows Isaksen and the second and third authors to compute the stable homotopy groups of spheres at least to the 90-stem, with ongoing computations into even higher dimensions.Comment: Accepted version, 85 page
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