\documentclass[12pt,titlepage]{article} \usepackage{amsmath} \usepackage{mathrsfs} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsthm} \usepackage{mathtools} \usepackage{graphicx} \usepackage{color} \usepackage{ucs} \usepackage[utf8x]{inputenc} \usepackage{xparse} \usepackage{hyperref} %----Macros---------- % % Unresolved issues: % % \righttoleftarrow % \lefttorightarrow % % \color{} with HTML colorspec % \bgcolor % \array with options (without options, it's equivalent to the matrix environment) % Of the standard HTML named colors, white, black, red, green, blue and yellow % are predefined in the color package. Here are the rest. \definecolor{aqua}{rgb}{0, 1.0, 1.0} \definecolor{fuschia}{rgb}{1.0, 0, 1.0} \definecolor{gray}{rgb}{0.502, 0.502, 0.502} \definecolor{lime}{rgb}{0, 1.0, 0} \definecolor{maroon}{rgb}{0.502, 0, 0} \definecolor{navy}{rgb}{0, 0, 0.502} \definecolor{olive}{rgb}{0.502, 0.502, 0} \definecolor{purple}{rgb}{0.502, 0, 0.502} \definecolor{silver}{rgb}{0.753, 0.753, 0.753} \definecolor{teal}{rgb}{0, 0.502, 0.502} % Because of conflicts, \space and \mathop are converted to % \itexspace and \operatorname during preprocessing. % itex: \space{ht}{dp}{wd} % % Height and baseline depth measurements are in units of tenths of an ex while % the width is measured in tenths of an em. \makeatletter \newdimen\itex@wd% \newdimen\itex@dp% \newdimen\itex@thd% \def\itexspace#1#2#3{\itex@wd=#3em% \itex@wd=0.1\itex@wd% \itex@dp=#2ex% \itex@dp=0.1\itex@dp% \itex@thd=#1ex% \itex@thd=0.1\itex@thd% \advance\itex@thd\the\itex@dp% \makebox[\the\itex@wd]{\rule[-\the\itex@dp]{0cm}{\the\itex@thd}}} \makeatother % \tensor and \multiscript \makeatletter \newif\if@sup \newtoks\@sups \def\append@sup#1{\edef\act{\noexpand\@sups={\the\@sups #1}}\act}% \def\reset@sup{\@supfalse\@sups={}}% \def\mk@scripts#1#2{\if #2/ \if@sup ^{\the\@sups}\fi \else% \ifx #1_ \if@sup ^{\the\@sups}\reset@sup \fi {}_{#2}% \else \append@sup#2 \@suptrue \fi% \expandafter\mk@scripts\fi} \def\tensor#1#2{\reset@sup#1\mk@scripts#2_/} \def\multiscripts#1#2#3{\reset@sup{}\mk@scripts#1_/#2% \reset@sup\mk@scripts#3_/} \makeatother % \slash \makeatletter \newbox\slashbox \setbox\slashbox=\hbox{$/$} \def\itex@pslash#1{\setbox\@tempboxa=\hbox{$#1$} \@tempdima=0.5\wd\slashbox \advance\@tempdima 0.5\wd\@tempboxa \copy\slashbox \kern-\@tempdima \box\@tempboxa} \def\slash{\protect\itex@pslash} \makeatother % math-mode versions of \rlap, etc % from Alexander Perlis, "A complement to \smash, \llap, and lap" % http://math.arizona.edu/~aprl/publications/mathclap/ \def\clap#1{\hbox to 0pt{\hss#1\hss}} \def\mathllap{\mathpalette\mathllapinternal} \def\mathrlap{\mathpalette\mathrlapinternal} \def\mathclap{\mathpalette\mathclapinternal} \def\mathllapinternal#1#2{\llap{$\mathsurround=0pt#1{#2}$}} \def\mathrlapinternal#1#2{\rlap{$\mathsurround=0pt#1{#2}$}} \def\mathclapinternal#1#2{\clap{$\mathsurround=0pt#1{#2}$}} % Renames \sqrt as \oldsqrt and redefine root to result in \sqrt[#1]{#2} \let\oldroot\root \def\root#1#2{\oldroot #1 \of{#2}} \renewcommand{\sqrt}[2][]{\oldroot #1 \of{#2}} % Manually declare the txfonts symbolsC font \DeclareSymbolFont{symbolsC}{U}{txsyc}{m}{n} \SetSymbolFont{symbolsC}{bold}{U}{txsyc}{bx}{n} \DeclareFontSubstitution{U}{txsyc}{m}{n} % Manually declare the stmaryrd font \DeclareSymbolFont{stmry}{U}{stmry}{m}{n} \SetSymbolFont{stmry}{bold}{U}{stmry}{b}{n} % Manually declare the MnSymbolE font \DeclareFontFamily{OMX}{MnSymbolE}{} \DeclareSymbolFont{mnomx}{OMX}{MnSymbolE}{m}{n} \SetSymbolFont{mnomx}{bold}{OMX}{MnSymbolE}{b}{n} \DeclareFontShape{OMX}{MnSymbolE}{m}{n}{ <-6> MnSymbolE5 <6-7> MnSymbolE6 <7-8> MnSymbolE7 <8-9> MnSymbolE8 <9-10> MnSymbolE9 <10-12> MnSymbolE10 <12-> MnSymbolE12}{} % Declare specific arrows from txfonts without loading the full package \makeatletter \def\re@DeclareMathSymbol#1#2#3#4{% \let#1=\undefined \DeclareMathSymbol{#1}{#2}{#3}{#4}} \re@DeclareMathSymbol{\neArrow}{\mathrel}{symbolsC}{116} \re@DeclareMathSymbol{\neArr}{\mathrel}{symbolsC}{116} \re@DeclareMathSymbol{\seArrow}{\mathrel}{symbolsC}{117} \re@DeclareMathSymbol{\seArr}{\mathrel}{symbolsC}{117} \re@DeclareMathSymbol{\nwArrow}{\mathrel}{symbolsC}{118} \re@DeclareMathSymbol{\nwArr}{\mathrel}{symbolsC}{118} \re@DeclareMathSymbol{\swArrow}{\mathrel}{symbolsC}{119} \re@DeclareMathSymbol{\swArr}{\mathrel}{symbolsC}{119} \re@DeclareMathSymbol{\nequiv}{\mathrel}{symbolsC}{46} \re@DeclareMathSymbol{\Perp}{\mathrel}{symbolsC}{121} \re@DeclareMathSymbol{\Vbar}{\mathrel}{symbolsC}{121} \re@DeclareMathSymbol{\sslash}{\mathrel}{stmry}{12} \re@DeclareMathSymbol{\bigsqcap}{\mathop}{stmry}{"64} \re@DeclareMathSymbol{\biginterleave}{\mathop}{stmry}{"6} \re@DeclareMathSymbol{\invamp}{\mathrel}{symbolsC}{77} \re@DeclareMathSymbol{\parr}{\mathrel}{symbolsC}{77} \makeatother % \llangle, \rrangle, \lmoustache and \rmoustache from MnSymbolE \makeatletter \def\Decl@Mn@Delim#1#2#3#4{% \if\relax\noexpand#1% \let#1\undefined \fi \DeclareMathDelimiter{#1}{#2}{#3}{#4}{#3}{#4}} \def\Decl@Mn@Open#1#2#3{\Decl@Mn@Delim{#1}{\mathopen}{#2}{#3}} \def\Decl@Mn@Close#1#2#3{\Decl@Mn@Delim{#1}{\mathclose}{#2}{#3}} \Decl@Mn@Open{\llangle}{mnomx}{'164} \Decl@Mn@Close{\rrangle}{mnomx}{'171} \Decl@Mn@Open{\lmoustache}{mnomx}{'245} \Decl@Mn@Close{\rmoustache}{mnomx}{'244} \makeatother % Widecheck \makeatletter \DeclareRobustCommand\widecheck[1]{{\mathpalette\@widecheck{#1}}} \def\@widecheck#1#2{% \setbox\z@\hbox{\m@th$#1#2$}% \setbox\tw@\hbox{\m@th$#1% \widehat{% \vrule\@width\z@\@height\ht\z@ \vrule\@height\z@\@width\wd\z@}$}% \dp\tw@-\ht\z@ \@tempdima\ht\z@ \advance\@tempdima2\ht\tw@ \divide\@tempdima\thr@@ \setbox\tw@\hbox{% \raise\@tempdima\hbox{\scalebox{1}[-1]{\lower\@tempdima\box \tw@}}}% {\ooalign{\box\tw@ \cr \box\z@}}} \makeatother % \mathraisebox{voffset}[height][depth]{something} \makeatletter \NewDocumentCommand\mathraisebox{moom}{% \IfNoValueTF{#2}{\def\@temp##1##2{\raisebox{#1}{$\m@th##1##2$}}}{% \IfNoValueTF{#3}{\def\@temp##1##2{\raisebox{#1}[#2]{$\m@th##1##2$}}% }{\def\@temp##1##2{\raisebox{#1}[#2][#3]{$\m@th##1##2$}}}}% \mathpalette\@temp{#4}} \makeatletter % udots (taken from yhmath) \makeatletter \def\udots{\mathinner{\mkern2mu\raise\p@\hbox{.} \mkern2mu\raise4\p@\hbox{.}\mkern1mu \raise7\p@\vbox{\kern7\p@\hbox{.}}\mkern1mu}} \makeatother %% Fix array \newcommand{\itexarray}[1]{\begin{matrix}#1\end{matrix}} %% \itexnum is a noop \newcommand{\itexnum}[1]{#1} %% Renaming existing commands \newcommand{\underoverset}[3]{\underset{#1}{\overset{#2}{#3}}} \newcommand{\widevec}{\overrightarrow} \newcommand{\darr}{\downarrow} \newcommand{\nearr}{\nearrow} \newcommand{\nwarr}{\nwarrow} \newcommand{\searr}{\searrow} \newcommand{\swarr}{\swarrow} \newcommand{\curvearrowbotright}{\curvearrowright} \newcommand{\uparr}{\uparrow} \newcommand{\downuparrow}{\updownarrow} \newcommand{\duparr}{\updownarrow} \newcommand{\updarr}{\updownarrow} \newcommand{\gt}{>} \newcommand{\lt}{<} \newcommand{\map}{\mapsto} \newcommand{\embedsin}{\hookrightarrow} \newcommand{\Alpha}{A} \newcommand{\Beta}{B} \newcommand{\Zeta}{Z} \newcommand{\Eta}{H} \newcommand{\Iota}{I} \newcommand{\Kappa}{K} \newcommand{\Mu}{M} \newcommand{\Nu}{N} \newcommand{\Rho}{P} \newcommand{\Tau}{T} \newcommand{\Upsi}{\Upsilon} \newcommand{\omicron}{o} \newcommand{\lang}{\langle} \newcommand{\rang}{\rangle} \newcommand{\Union}{\bigcup} \newcommand{\Intersection}{\bigcap} \newcommand{\Oplus}{\bigoplus} \newcommand{\Otimes}{\bigotimes} \newcommand{\Wedge}{\bigwedge} \newcommand{\Vee}{\bigvee} \newcommand{\coproduct}{\coprod} \newcommand{\product}{\prod} \newcommand{\closure}{\overline} \newcommand{\integral}{\int} \newcommand{\doubleintegral}{\iint} \newcommand{\tripleintegral}{\iiint} \newcommand{\quadrupleintegral}{\iiiint} \newcommand{\conint}{\oint} \newcommand{\contourintegral}{\oint} \newcommand{\infinity}{\infty} \newcommand{\bottom}{\bot} \newcommand{\minusb}{\boxminus} \newcommand{\plusb}{\boxplus} \newcommand{\timesb}{\boxtimes} \newcommand{\intersection}{\cap} \newcommand{\union}{\cup} \newcommand{\Del}{\nabla} \newcommand{\odash}{\circleddash} \newcommand{\negspace}{\!} \newcommand{\widebar}{\overline} \newcommand{\textsize}{\normalsize} \renewcommand{\scriptsize}{\scriptstyle} \newcommand{\scriptscriptsize}{\scriptscriptstyle} \newcommand{\mathfr}{\mathfrak} \newcommand{\statusline}[2]{#2} \newcommand{\tooltip}[2]{#2} \newcommand{\toggle}[2]{#2} % Theorem Environments \theoremstyle{plain} \newtheorem{theorem}{Theorem} \newtheorem{lemma}{Lemma} \newtheorem{prop}{Proposition} \newtheorem{cor}{Corollary} \newtheorem*{utheorem}{Theorem} \newtheorem*{ulemma}{Lemma} \newtheorem*{uprop}{Proposition} \newtheorem*{ucor}{Corollary} \theoremstyle{definition} \newtheorem{defn}{Definition} \newtheorem{example}{Example} \newtheorem*{udefn}{Definition} \newtheorem*{uexample}{Example} \theoremstyle{remark} \newtheorem{remark}{Remark} \newtheorem{note}{Note} \newtheorem*{uremark}{Remark} \newtheorem*{unote}{Note} %------------------------------------------------------------------- \begin{document} %------------------------------------------------------------------- \section*{n-excisive (∞,1)-functor} \hypertarget{context}{}\subsubsection*{{Context}}\label{context} \hypertarget{goodwillie_calculus}{}\paragraph*{{Goodwillie calculus}}\label{goodwillie_calculus} [[!include Goodwillie calculus - contents]] \hypertarget{contents}{}\section*{{Contents}}\label{contents} \noindent\hyperlink{definition}{Definition}\dotfill \pageref*{definition} \linebreak \noindent\hyperlink{cocartesian_cubical_diagrams}{(Co-)Cartesian cubical diagrams}\dotfill \pageref*{cocartesian_cubical_diagrams} \linebreak \noindent\hyperlink{excisive_functors}{$n$-Excisive functors}\dotfill \pageref*{excisive_functors} \linebreak \noindent\hyperlink{properties}{Properties}\dotfill \pageref*{properties} \linebreak \noindent\hyperlink{nExcisiveApproximation}{$n$-Excisive approximation and reflection}\dotfill \pageref*{nExcisiveApproximation} \linebreak \noindent\hyperlink{homogeneous_pieces}{Homogeneous pieces}\dotfill \pageref*{homogeneous_pieces} \linebreak \noindent\hyperlink{examples}{Examples}\dotfill \pageref*{examples} \linebreak \noindent\hyperlink{GoodwillienJets}{Goodwillie $n$-jets}\dotfill \pageref*{GoodwillienJets} \linebreak \noindent\hyperlink{related_concepts}{Related concepts}\dotfill \pageref*{related_concepts} \linebreak \noindent\hyperlink{references}{References}\dotfill \pageref*{references} \linebreak \hypertarget{definition}{}\subsection*{{Definition}}\label{definition} \hypertarget{cocartesian_cubical_diagrams}{}\subsubsection*{{(Co-)Cartesian cubical diagrams}}\label{cocartesian_cubical_diagrams} Let $\mathcal{C}$ be an [[(∞,1)-category]] with [[finite (∞,1)-colimits]]. \begin{defn} \label{StronglyCoCartesian}\hypertarget{StronglyCoCartesian}{} An $n$-[[cube]] in $\mathcal{C}$, hence an [[(∞,1)-functor]] $\Box^n \longrightarrow \mathcal{C}$, is called \emph{strongly homotopy co-cartesian} or just \emph{strongly co-cartesian}, if all its 2-dimensional square faces are [[homotopy pushout]] [[diagrams]] in $\mathcal{C}$. \end{defn} \begin{defn} \label{Cartesian}\hypertarget{Cartesian}{} An $n$-[[cube]] in $\mathcal{D}$, hence an [[(∞,1)-functor]] $\Box^n \longrightarrow \mathcal{D}$, is called \emph{homotopy cartesian} or just \emph{cartesian}, if its ``first'' object exhibits a [[homotopy limit]]-[[cone]] over the remaining objects. \end{defn} (e.g. \hyperlink{HigherAlg}{Lurie, def. 6.1.1.2 with prop. 6.1.1.15}) \hypertarget{excisive_functors}{}\subsubsection*{{$n$-Excisive functors}}\label{excisive_functors} \begin{defn} \label{}\hypertarget{}{} An [[(∞,1)-functor]] $F \colon \mathcal{C} \longrightarrow \mathcal{D}$ is \textbf{$n$-excisive} for $n \in \mathbb{N}$ (or \emph{polynomial} of degree at most $n$) if whenever $X$ is a strongly cocartesian $(n + 1)$-[[cube]] in $\mathcal{C}$, def. \ref{StronglyCoCartesian}, then $F(X)$ is a cartesian cube in $\mathcal{D}$, def. \ref{Cartesian}. A 1-excisive (∞,1)-functor is often just called \emph{[[excisive (∞,1)-functor]]} for short. \end{defn} An $(\infty,1)$-functor which is $n$-excisive for some $n \in \mathbb{N}$ is also called a \textbf{polynomial (∞,1)-functor} (not to be confused with [[polynomial (∞,1)-functor|other concepts having the same name]]). It has \textbf{degree $k$} when the smallest value of $n$ for which it is $n$-excisive is $k$. \begin{remark} \label{}\hypertarget{}{} This notion is comparable to how a [[polynomial]] of degree at most $n$ is determined by its values on $n + 1$ distinct points. \end{remark} \hypertarget{properties}{}\subsection*{{Properties}}\label{properties} \hypertarget{nExcisiveApproximation}{}\subsubsection*{{$n$-Excisive approximation and reflection}}\label{nExcisiveApproximation} Let $\mathcal{C}$ be an [[(∞,1)-category]] with [[finite (∞,1)-colimits]] and a [[terminal object in an (∞,1)-category|terminal object]], and let $\mathcal{D}$ be a [[Goodwillie-differentiable (∞,1)-category]]. \begin{defn} \label{InclusionOfNExcisive}\hypertarget{InclusionOfNExcisive}{} For $n \in \mathbb{N}$ \begin{displaymath} Exc^n(\mathcal{C}, \mathcal{D}) \hookrightarrow Func(\mathcal{C}, \mathcal{D}) \end{displaymath} for the [[full sub-(∞,1)-category]] of the [[(∞,1)-functor (∞,1)-category]] on those [[(∞,1)-functors]] which are $n$-excisive. \end{defn} \begin{prop} \label{nExcisiveApproximations}\hypertarget{nExcisiveApproximations}{} The inclusion of def. \ref{InclusionOfNExcisive} is [[left exact (∞,1)-functor|lex]] [[reflective sub-(∞,1)-category|reflective]], hence the inclusion functor has a [[left adjoint|left]] [[adjoint (∞,1)-functor]] \begin{displaymath} P_n \;\colon\; Func(\mathcal{C}, \mathcal{D}) \longrightarrow Exc^n(\mathcal{C}, \mathcal{D}) \end{displaymath} which moreover is [[left exact (infinity,1)-functor|left exact]] (preserves [[finite (∞,1)-limits]]). \end{prop} This is essentially the statement of (\hyperlink{Goodwillie03}{Goodwillie 03, theorem 1.8}). In the above form it appears explicitly as (\hyperlink{HigherAlg}{Lurie, theorem 6.1.1.10}). The construction of the reflector $P_n$ is in (\hyperlink{HigherAlg}{Lurie, constrution 6.1.1.27}). For $n = 1$ this reflection is \emph{[[spectrification]]}. \begin{cor} \label{}\hypertarget{}{} For $\mathcal{D} = \mathbf{H}$ an [[(∞,1)-topos]], then for all $n \in \mathbb{N}$ we have that \begin{displaymath} Exc^n(\mathcal{C}, \mathbf{H}) \in (\infty,1)Topos \end{displaymath} is an [[(∞,1)-topos]]. (For $n \gt 1$ this is in general \emph{not} a [[hypercomplete (∞,1)-topos]], even if $\mathbf{H}$ is.) \end{cor} This observation is due to [[Charles Rezk]]. It appears as (\hyperlink{HigherAlg}{Lurie, remark 6.1.1.11}). \begin{remark} \label{}\hypertarget{}{} A [[site]] of definition of $Exc^n(\mathcal{C}, \mathbf{H}) \hookrightarrow PSh(\mathcal{C}^{op}, \mathbf{H})$ is the \emph{[[Weiss topology]]} on $\mathcal{C}^{op}$. \end{remark} \begin{remark} \label{}\hypertarget{}{} As $n$ ranges, the tower of $n$-excisive approximations of an $(\infty,1)$-functor, accordding to prop. \ref{nExcisiveApproximations}, forms a tower [[analogy|analogous]] to the the [[Taylor series]] of a [[smooth function]]. This is called the [[Goodwillie-Taylor tower]] \begin{displaymath} \cdots \to P_{n+1} F \to P_n F \to \cdots \to P_1 F \to P_0 F \,. \end{displaymath} If this converges to $F$, then $F$ is analogous to an [[analytic function]] and is called an \emph{[[analytic (∞,1)-functor]]}. \end{remark} \begin{defn} \label{}\hypertarget{}{} In the situation of def. \ref{nExcisiveApproximations}, the functors $F$ for which $P_{n-1}F \simeq \ast$ (hence the $P_{n-1}$ [[anti-modal types]]) are called $n$-[[reduced (∞,1)-functors]]. \end{defn} (e.g. \hyperlink{HigherAlg}{Lurie, def. 6.1.2.1}) \hypertarget{homogeneous_pieces}{}\subsubsection*{{Homogeneous pieces}}\label{homogeneous_pieces} A polynomial $\infty$-functor of degree $k$ --- that is, a $k$-excisive functor which is not $n$-excisive for any $n\lt k$ --- is a \textbf{homogeneous} polynomial if its approximation by an $(k-1)$ degree polynomial is trivial. (\ldots{}) \begin{prop} \label{}\hypertarget{}{} Let $\mathcal{C}$ be an [[(∞,1)-category]] with [[finite (∞,1)-colimits]] and with [[terminal object in an (∞,1)-category|terninal object]]. Let $\mathcal{D}$ be a [[pointed category|pointed]] [[Goodwillie-differentiable (∞,1)-category]]. Write $\mathcal{C}^{\ast/}$ for the [[pointed objects]] in $\mathcal{C}$. Then for all natural numbers $n \geq 1$ composition with the [[forgetful functor]] $\mathcal{C}^{\ast/} \to \mathcal{C}$ induces an [[equivalence of (∞,1)-categories]] \begin{displaymath} Homog^n(\mathcal{C},\mathcal{D}) \stackrel{\simeq}{\longrightarrow} Homog^n(\mathcal{C}^{\ast/}, \mathcal{D}) \end{displaymath} \end{prop} (\hyperlink{HigherAlg}{Lurie, prop. 6.1.2.11}) \hypertarget{examples}{}\subsection*{{Examples}}\label{examples} \hypertarget{GoodwillienJets}{}\subsubsection*{{Goodwillie $n$-jets}}\label{GoodwillienJets} Write $\infty Grpd_{fin}$ for the [[(∞,1)-category]] of [[finite homotopy types]], hence those freely generated by [[finite (∞,1)-colimits]] from the point. Write $\infty Grpd_{fin}^{\ast/}$ for the [[pointed object|pointed]] finite homotopy types. \begin{example} \label{}\hypertarget{}{} For $\mathbf{H}$ an [[(∞,1)-topos]] we have that \begin{itemize}% \item $Exc^0(\infty Grpd_{fin}^{\ast/},\mathbf{H}) \simeq \mathbf{H}$ is the collection of constant functors, hence the original [[(∞,1)-topos]] itself; \item $Exc^1(\infty Grpd_{fin}^{\ast/},\mathbf{H}) \simeq T\mathbf{H}$ is the collection of [[parameterized spectra]] in $\mathbf{H}$, hence the [[tangent (∞,1)-topos]] of $\mathbf{H}$. \end{itemize} Hence one might refer to the tower of toposes \begin{displaymath} \cdots \to J^n \mathbf{H} \to \cdots \to J^2 \mathbf{H} \to T \mathbf{H} \to \mathbf{H} \end{displaymath} with \begin{displaymath} J^n \mathbf{H} \coloneqq Exc^n(\infty Grpd^{\ast/}, \mathbf{H}) \end{displaymath} the tower of ``[[Goodwillie calculus|Goodwillie]] [[jet (∞,1)-categories]]'' of $\mathbf{H}$. \end{example} see (\hyperlink{HigherAlg}{Lurie, def. 1.4.2.8 and around p. 823}) \hypertarget{related_concepts}{}\subsection*{{Related concepts}}\label{related_concepts} \begin{itemize}% \item [[excisive (∞,1)-functor]] \item [[Goodwillie calculus]] \begin{itemize}% \item [[Goodwillie-Taylor tower]] \item [[analytic (∞,1)-functor]] \end{itemize} \item [[polynomial (∞,1)-functor]] \item [[model structure for n-excisive functors]] \end{itemize} \hypertarget{references}{}\subsection*{{References}}\label{references} The notion of $n$-excisive functors was introduced in \begin{itemize}% \item [[Thomas Goodwillie]], \emph{Calculus II, Analytic functors}, K-Theory 5 (1991/92), no. 4, 295-332 \end{itemize} The [[Taylor tower]] formed by $n$-excisive functors was then studied in \begin{itemize}% \item [[Thomas Goodwillie]], \emph{Calculus III: Taylor Series}, Geom. Topol. 7(2003) 645-711 (\href{http://arxiv.org/abs/math/0310481}{arXiv:math/0310481}) \end{itemize} See also \begin{itemize}% \item [[Charles Rezk]], \emph{A streamlined proof of Goodwillie's $n$-excisive approximation} (\href{http://arxiv.org/abs/0812.1324}{arXiv:0812.1324}) \end{itemize} A discussion in the general abstract context of [[(∞,1)-category theory]] is in \begin{itemize}% \item [[Jacob Lurie]], section 6.1.1 of \emph{[[Higher Algebra]]} \end{itemize} A [[model structure for n-excisive functors]] is given in \begin{itemize}% \item [[Georg Biedermann]], [[Boris Chorny]], Oliver R\"o{}ndigs, \emph{Calculus of functors and model categories}, Advances in Mathematics 214 (2007) 92-115 (\href{http://arxiv.org/abs/math/0601221}{arXiv:math/0601221}) \item [[Georg Biedermann]], Oliver R\"o{}ndigs, \emph{Calculus of functors and model categories II} (\href{http://arxiv.org/abs/1305.2834v2}{arXiv:1305.2834v2}) \end{itemize} Relation to [[Mackey functors]] is discussed in \begin{itemize}% \item [[Saul Glasman]], \emph{Goodwillie calculus and Mackey functors} (\href{https://arxiv.org/abs/1610.03127}{arXiv:1610.03127}) \end{itemize} [[!redirects n-excisive (∞,1)-functors]] [[!redirects n-excisive (infinity,1)-functor]] [[!redirects n-excisive (infinity,1)-functors]] [[!redirects n-excisive functor]] [[!redirects n-excisive functors]] [[!redirects n-excisive approximation]] [[!redirects n-excisive approximations]] \end{document}