ﻻ يوجد ملخص باللغة العربية
Let $X$ be a simply connected space with finite-dimensional rational homotopy groups. Let $p_infty colon UE to mathrm{Baut}_1(X)$ be the universal fibration of simply connected spaces with fibre $X$. We give a DG Lie model for the evaluation map $ omega colon mathrm{aut}_1(mathrm{Baut}_1(X_{mathbb Q})) to mathrm{Baut}_1(X_{mathbb Q})$ expressed in terms of derivations of the relative Sullivan model of $p_infty$. We deduce formulas for the rational Gottlieb group and for the evaluation subgroups of the classifying space $mathrm{Baut}_1(X_{mathbb Q})$ as a consequence. We also prove that ${mathbb C} P^n_{mathbb Q}$ cannot be realized as $mathrm{Baut}_1(X_{mathbb Q})$ for $n leq 4$ and $X$ with finite-dimensional rational homotopy groups.
Digital topology is part of the ongoing endeavour to understand and analyze digitized images. With a view to supporting this endeavour, many notions from algebraic topology have been introduced into the setting of digital topology. But some of the mo
We study localization at a prime in homotopy type theory, using self maps of the circle. Our main result is that for a pointed, simply connected type $X$, the natural map $X to X_{(p)}$ induces algebraic localizations on all homotopy groups. In order
We prove that the sectional category of the universal fibration with fibre X, for X any space that satisfies a well-known conjecture of Halperin, equals one after rationalization.
Let $G$ be a discrete group. We prove that the category of $G$-posets admits a model structure that is Quillen equivalent to the standard model structure on $G$-spaces. As is already true nonequivariantly, the three classes of maps defining the model
We define in the setting of homotopy type theory an H-space structure on $mathbb S^3$. Hence we obtain a description of the quaternionic Hopf fibration $mathbb S^3hookrightarrowmathbb S^7twoheadrightarrowmathbb S^4$, using only homotopy invariant tools.