Zobrazeno 1 - 10
of 1 832
pro vyhledávání: '"Christensen, J P"'
We develop the theory of Yoneda Ext groups over a ring in homotopy type theory (HoTT) and describe their interpretation into an $\infty$-topos. This is an abstract approach to Ext groups which does not require projective or injective resolutions. Whi
Externí odkaz:
http://arxiv.org/abs/2305.09639
We introduce and study central types, which are generalizations of Eilenberg-Mac Lane spaces. A type is central when it is equivalent to the component of the identity among its own self-equivalences. From centrality alone we construct an infinite del
Externí odkaz:
http://arxiv.org/abs/2301.02636
Autor:
Christensen, J. Daniel
Publikováno v:
Journal of Topology 17(2) (2024)
In a 2005 paper, Casacuberta, Scevenels and Smith construct a homotopy idempotent functor $E$ on the category of simplicial sets with the property that whether it can be expressed as localization with respect to a map $f$ is independent of the ZFC ax
Externí odkaz:
http://arxiv.org/abs/2109.06670
Autor:
Christensen, J. Daniel, Wu, Enxin
We explore several notions of $k$-form at a point in a diffeological space, construct bundles of such $k$-forms, and compare sections of these bundles to differential forms. As they are defined locally, our $k$-forms can contain more information than
Externí odkaz:
http://arxiv.org/abs/2009.01770
Publikováno v:
Journal of Pure and Applied Algebra 226(3) (2022), 106846, 33 pages
In a triangulated category, cofibre fill-ins always exist. Neeman showed that there is always at least one "good" fill-in, i.e., one whose mapping cone is exact. Verdier constructed a fill-in of a particular form in his proof of the $4 \times 4$ lemm
Externí odkaz:
http://arxiv.org/abs/2008.03643
Autor:
Christensen, J. Daniel, Rijke, Egbert
Publikováno v:
Journal of Pure and Applied Algebra 226(3) (2022), 106848, 21 pages
A reflective subuniverse in homotopy type theory is an internal version of the notion of a localization in topology or in the theory of $\infty$-categories. Working in homotopy type theory, we give new characterizations of the following conditions on
Externí odkaz:
http://arxiv.org/abs/2008.03538
Autor:
Christensen, J. Daniel, Scoccola, Luis
Publikováno v:
Algebr. Geom. Topol. 23 (2023) 2107-2140
We prove the Hurewicz theorem in homotopy type theory, i.e., that for $X$ a pointed, $(n-1)$-connected type $(n \geq 1)$ and $A$ an abelian group, there is a natural isomorphism $\pi_n(X)^{ab} \otimes A \cong \tilde{H}_n(X; A)$ relating the abelianiz
Externí odkaz:
http://arxiv.org/abs/2007.05833
Autor:
Arlin, Kevin, Christensen, J. Daniel
Publikováno v:
Algebr. Geom. Topol. 23 (2023) 2975-2991
We show that the homotopy category of unpointed spaces admits no set of objects jointly reflecting isomorphisms by giving an explicit counterexample involving large symmetric groups. We also show that, in contrast, the spheres jointly reflect equival
Externí odkaz:
http://arxiv.org/abs/1910.04141
Traumatic injuries are measured using the Abbreviated Injury Scale (AIS), which is a risk to life scale. New human computer models use stresses and strains to evaluate whether serious or fatal injuries are reached, unfortunately these tensors bear no
Externí odkaz:
http://arxiv.org/abs/1904.00919
Publikováno v:
Clinical Epidemiology, Vol Volume 15, Pp 123-136 (2023)
Yuelian Sun,1– 4 Jesper Padkær Petersen,5 Chunsen Wu,6,7 Julie Werenberg Dreier,3,8 Rikke Damkjær Maimburg,9– 11 Tine Brink Henriksen,5 Jakob Christensen1,2 1Department of Neurology, Aarhus University Hospital, Aarhus, Denmark; 2Department of C
Externí odkaz:
https://doaj.org/article/db0a56271fd340508463da5eced442dc
