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Enhanced twisted arrow categories. (English) Zbl 1520.18018

This paper aims to provide a description of the \(\infty\)-category of natural transformations \(\mathrm{Nat}\left( F,G\right) \)as an end for any functors \(F\)and \(G\)from an \(\infty\)-category to an \(\infty\)-bicategory.
The synopsis of the paper goes as follows.
§ 1
is concerned with preliminaries.
§ 2
gives the formal definition of Tw\(\left( \mathbb{C} \right) \), establishing that \[ \mathrm{Tw}\left( \mathbb{C}\right) \rightarrow\mathbb{C}\times\mathbb{C} \] is a Cartesian fibration.
§ 3
proves that this Cartesian fibration classifies precisely the enhanced mapping functor \[ \mathcal{C}^{\mathrm{op}}\times\mathcal{C}\rightarrow\mathbb{C}^{\mathrm{op} }\times\mathbb{C}\rightarrow\mathfrak{C}at_{\infty} \] where \(\mathfrak{C}at_{\infty}\)is the \(\left( \infty,2\right) \)-category of \(\infty\)-categories. The proof is highly technical, freely uses results from [J. Lurie, “\((\infty,2)\)-categories and the Goodwillie calculus I”, Preprint, arXiv:0905.0462] and [A. Gagna et al., J. Lond. Math. Soc., II. Ser. 106, No. 3, 1920–1982 (2022; Zbl 1518.18020)].
§ 4
turns to the true aim of the paper, establishing that, given two functors \[ F,G:\mathcal{C}\rightarrow\mathbb{D} \] from an \(\infty\)-category to an \(\left( \infty,2\right) \)-category, the \(\infty\)-category of natural transformations between them can be expressed as an end \[ \mathrm{Nat}\left( F,G\right) \simeq\mathrm{lim}_{\mathrm{Tw}\left( \mathcal{C}\right) ^{\mathrm{op}}}\mathrm{Map}_{\mathbb{D}}\left( F\left( -\right) ,G\left( -\right) \right) \] The proof is highly technical, making use of a wide variety of techniques native to the contexts of scaled simplicial sets and marked simplicial sets. This result allows of analyzing in greater detail the theory of weighted colimits of \(\mathfrak{C}at_{\infty}\)-valued functors exposed in [D. Gepner et al., Doc. Math. 22, 1225–1266 (2017; Zbl 1390.18021)], showing that this definition coincides with the definition provided by the first author [J. Homotopy Relat. Struct. 17, No. 1, 1–22 (2022; Zbl 1505.18030)].

MSC:

18N10 2-categories, bicategories, double categories
18N60 \((\infty,1)\)-categories (quasi-categories, Segal spaces, etc.); \(\infty\)-topoi, stable \(\infty\)-categories
18N65 \((\infty, n)\)-categories and \((\infty,\infty)\)-categories

References:

[1] Abellán García, F., Dyckerhoff, T., and Stern, W. H. “A relative 2-nerve”. Algebr. Geom. Topol. 20-6 (2020) pp. 3147-3182 · Zbl 1460.18020
[2] Abellán García, F. and Stern, W. H. Theorem A for marked 2-categories. J. Pure & Applied Algebra, Vol. 226, Issue 9, 2022 · Zbl 1495.18026
[3] Abellán García, F. and Stern, W. H. “2-Cartesian fibrations II: Higher cofinal-ity”. 2022. arXiv:2201.09589
[4] Abellán García, F. Marked colimits and higher cofinality. Homotopy Relat. Struct. 17, 1-22 (2022). DOI: s40062-021-00296-2 · Zbl 1505.18030 · doi:10.1007/s40062-021-00296-2
[5] Barwick, C., Glasman, S. , and Nardin, D. “Dualizing cartesian and cocartesian fibrations”. Theory and Applications of Categories. Vol. 33 No. 4 (2018), pp. 67-94. · Zbl 1423.18025
[6] Dyckerhoff, T. and Kapranov, M. “Higher Segal Spaces”. Springer Lecture Notes in Mathematics 2244. Springer, 2019. · Zbl 1459.18001
[7] Barwick, C. “Spectral Mackey Functors and equivariant Algebraic K-Theory (I).” Advances in Mathematics Vol. 304 (Jan. 2017), pp. 646-727. · Zbl 1348.18020
[8] Cisinski, D. “Higher Categories and Homotopical Algebra.” Cambridge University Press, 2019. · Zbl 1430.18001
[9] Dugger, D. and Spivak, David I. “Rigidification of quasi-categories”. Algebraic & Geometric Topology 11.1 (jan. 2011), pp. 225-261. doi: 10.2140/agt.2011.11.225. · Zbl 1213.55015 · doi:10.2140/agt.2011.11.225
[10] Dugger, D. “A primer on homotopy colimits”. University of Oregon, 2008.
[11] Gagna, A., Harpaz, Y., Lanari, E. “On the equivalence of all models for (∞, 2)-categories.” J. London Math. Soc. 2022.
[12] Gagna, A., Harpaz, Y., Lanari, E. “Fibrations and lax limits of (∞, 2)-categories.” 2020. arXiv:2012.04537
[13] Gepner, D., Haugseng R. and Nikolaus, T. “Lax colimits and free fibrations in ∞-categories”. Documenta Mathematica 1.15 (jan. 2015), vol 22. pp. 1225-1266 · Zbl 1390.18021
[14] Lurie, J. “Derived Algebraic Geometry X: Formal Moduli Problems” 2011 avail-able at the author’s webpage: DAG X
[15] Lurie, J. “(∞, 2)-categories and the Goodwillie Calculus”. 2009. arXiv: 0905.0462
[16] Lurie, J. “Higher Topos Theory”. Princeton University Press, 2009. · Zbl 1175.18001
[17] Lurie, J. “Higher Algebra”. 2017 Available at the author’s webpage.
[18] Lurie, J. “Kerodon”. 2022 https://kerodon.net This article may be accessed at http://www.tac.mta.ca/tac/
[19] Maria Manuel Clementino, Universidade de Coimbra: mmc@mat.uc.pt Valeria de Paiva, Nuance Communications Inc: valeria.depaiva@gmail.com Richard Garner, Macquarie University: richard.garner@mq.edu.au Ezra Getzler, Northwestern University: getzler (at) northwestern(dot)edu
[20] Dirk Hofmann, Universidade de Aveiro: dirk@ua.pt Joachim Kock, Universitat Autònoma de Barcelona: kock (at) mat.uab.cat Stephen Lack, Macquarie University: steve.lack@mq.edu.au Tom Leinster, University of Edinburgh: Tom.Leinster@ed.ac.uk Matias Menni, Conicet and Universidad Nacional de La Plata, Argentina: matias.menni@gmail.com Susan Niefield, Union College: niefiels@union.edu
[21] Kate Ponto, University of Kentucky: kate.ponto (at) uky.edu Robert Rosebrugh, Mount Allison University: rrosebrugh@mta.ca Jiří Rosický, Masaryk University: rosicky@math.muni.cz Giuseppe Rosolini, Università di Genova: rosolini@disi.unige.it Michael Shulman, University of San Diego: shulman@sandiego.edu Alex Simpson, University of Ljubljana: Alex.Simpson@fmf.uni-lj.si James Stasheff, University of North Carolina: jds@math.upenn.edu
[22] Tim Van der Linden, Université catholique de Louvain: tim.vanderlinden@uclouvain.be
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