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\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*{tangent cohesive (∞,1)-topos} \hypertarget{context}{}\subsubsection*{{Context}}\label{context} \hypertarget{cohesive_toposes}{}\paragraph*{{Cohesive $\infty$-Toposes}}\label{cohesive_toposes} [[!include cohesive infinity-toposes - contents]] \hypertarget{stable_homotopy_theory}{}\paragraph*{{Stable Homotopy theory}}\label{stable_homotopy_theory} [[!include stable homotopy theory - contents]] \hypertarget{contents}{}\section*{{Contents}}\label{contents} \noindent\hyperlink{idea}{Idea}\dotfill \pageref*{idea} \linebreak \noindent\hyperlink{properties}{Properties}\dotfill \pageref*{properties} \linebreak \noindent\hyperlink{StableExtensionOfCohesion}{Stable extension of cohesion}\dotfill \pageref*{StableExtensionOfCohesion} \linebreak \noindent\hyperlink{stable_homotopy_types}{Stable homotopy types}\dotfill \pageref*{stable_homotopy_types} \linebreak \noindent\hyperlink{Cohomology}{Cohomology -- Twisted bivariant generalized geometric cohomology theory}\dotfill \pageref*{Cohomology} \linebreak \noindent\hyperlink{CohesiveAndDifferentialRefinement}{Cohesive and differential refinement}\dotfill \pageref*{CohesiveAndDifferentialRefinement} \linebreak \noindent\hyperlink{related_concepts}{Related concepts}\dotfill \pageref*{related_concepts} \linebreak \noindent\hyperlink{references}{References}\dotfill \pageref*{references} \linebreak \hypertarget{idea}{}\subsection*{{Idea}}\label{idea} The [[tangent (∞,1)-category]] $T\mathbf{H}$ to a [[cohesive (∞,1)-topos]] is itself cohesive: the \emph{tangent cohesive (∞,1)-topos}. This $T \mathbf{H}$ is the $\infty$-topos of [[parameterized spectra]] in $\mathbf{H}$, hence is the context for cohesive [[stable homotopy theory]]. \hypertarget{properties}{}\subsection*{{Properties}}\label{properties} \hypertarget{StableExtensionOfCohesion}{}\subsubsection*{{Stable extension of cohesion}}\label{StableExtensionOfCohesion} Let $\mathbf{H}$ be a [[cohesive (∞,1)-topos]]. By the discussion at \emph{\href{tangent+%28infinity%2C1%29-category#TangentTopos}{tangent ∞-category -- Examples -- Of an ∞-topos}} the tangent $\infty$-topos $T \mathbf{H}$ constitutes an [[extension]] of $\mathbf{H}$ by its [[stabilization]] $Stab(\mathbf{H})$: \begin{displaymath} \itexarray{ && Stab(\mathbf{H}) & \stackrel{\overset{L\Pi^{seq}}{\longrightarrow}}{\stackrel{\overset{Disc^{seq}}{\leftarrow}}{\stackrel{\overset{\Gamma^{seq}}{\longrightarrow}}{\underset{coDisc^{seq}}{\leftarrow}}}} & Stab(\infty Grpd) \simeq Spectra \\ && \simeq && \simeq \\ && T_\ast \mathbf{H} && T_\ast \infty Grpd \\ && \downarrow^{\mathrlap{incl}} && \downarrow^{\mathrlap{incl}} \\ \mathbf{H} &\stackrel{\overset{d}{\longrightarrow}}{\underset{\Omega^\infty \circ tot}{\leftarrow}}& T \mathbf{H} & \stackrel{\overset{L\Pi^{seq}}{\longrightarrow}}{\stackrel{\overset{Disc^{seq}}{\leftarrow}}{\stackrel{\overset{\Gamma^{seq}}{\longrightarrow}}{\underset{coDisc^{seq}}{\leftarrow}}}} & T \infty Grpd \\ && {}^{\mathllap{base}}\downarrow \uparrow^{\mathrlap{0}} && {}^{\mathllap{base}}\downarrow \uparrow^{\mathrlap{0}} \\ && \mathbf{H} & \stackrel{\overset{\Pi}{\longrightarrow}}{\stackrel{\overset{Disc}{\leftarrow}}{\stackrel{\overset{\Gamma}{\longrightarrow}}{\underset{coDisc}{\leftarrow}}}} & \infty Grpd } \,. \end{displaymath} Here \begin{itemize}% \item $\Omega^\infty \circ tot \;\colon\; T \mathbf{H} \longrightarrow \mathbf{H}$ assigns the \emph{total space} of a spectrum bundle; its [[left adjoint]] is the \href{tangent+%28infinity%2C1%29-category#CotangentComplex}{tangent complex functor}; \item $base \;\colon\; T \mathbf{H} \longrightarrow \mathbf{H}$ assigns the \emph{base space} of a spectrum bundle; its [[left adjoint]] produces the 0-bundle; together these exhibit $T \mathbf{H}$ as an [[infinitesimal cohesive (infinity,1)-topos]] over $\mathbf{H}$. \end{itemize} \hypertarget{stable_homotopy_types}{}\subsubsection*{{Stable homotopy types}}\label{stable_homotopy_types} In a tangent cohesive $\infty$-topos $T \mathbf{H}$ all the [[homotopy types]] in $T_\ast \mathbf{H} \hookrightarrow T\mathbf{H}$ are [[stable homotopy types]]. \hypertarget{Cohomology}{}\subsubsection*{{Cohomology -- Twisted bivariant generalized geometric cohomology theory}}\label{Cohomology} Where the [[(∞,1)-categorical hom-space]] in a general [[(∞,1)-topos]] constitute a notion of [[cohomology]], those of a [[tangent (∞,1)-topos]] specifically constitute [[twisted generalized cohomology]], in fact [[twisted bivariant cohomology]]. For consider a [[spectrum object]] $E \in T_\ast \mathbf{H}$ and write $GL_1(E) \in Grp(\mathbf{H})$ for its [[∞-group of units]]. Then the [[∞-action]] of this on $E$ is (by the discussion there) exhibited by an object \begin{displaymath} \left( \itexarray{ E//GL_1(E) \\ \downarrow \\ \mathbf{B}GL_1(E) } \right) \;\;\; \in \;\;\; T_{\mathbf{B}GL_1(E)}\mathbf{H} \hookrightarrow T\mathbf{H} \,. \end{displaymath} More generally, for $Pic(E) \in \mathbf{H}$ the [[Picard ∞-groupoid]] of $E$ there is the universal [[(∞,1)-line bundle]] \begin{displaymath} (\widehat{Pic(E)} \to Pic(E)) \in T \mathbf{H} \,. \end{displaymath} Now for any object $X \in \mathbf{H}$ we have the trivial [[sphere spectrum]] [[spectrum bundle]] over $X$ \begin{displaymath} X \times \mathbb{S} \simeq \left( \itexarray{ X \times \mathbb{S} \\ \downarrow \\ X } \right) \;\;\; \in \;\;\; T_{X}\mathbf{H} \hookrightarrow T\mathbf{H} \,. \end{displaymath} then morphisms in $T \mathbf{H}$ from the latter to the former \begin{displaymath} \left( \itexarray{ X \times \mathbb{S} \\ \downarrow \\ X } \right) \longrightarrow \left( \itexarray{ E//GL_1(E) \\ \downarrow \\ \mathbf{B}GL_1(E) } \right) \end{displaymath} are equivalently [[homotopy]] [[commuting diagrams]] of the form \begin{displaymath} \itexarray{ X \times \mathbb{S} &\stackrel{\sigma}{\longrightarrow}& E//GL_1(E) \\ \downarrow && \downarrow \\ X &\stackrel{\chi}{\longrightarrow}& \mathbf{B}GL_1(E) } \end{displaymath} and hence \begin{enumerate}% \item a choice of [[twisted cohomology|twist of E-cohomology]] $\chi \;\colon \; X \longrightarrow \mathbf{B}GL_1(E)$, modulating a $GL_1(E)$-[[principal ∞-bundle]]; \item an element in the $\chi$-twisted $E$-cohomology of $X$, $\sigma \in E^{\bullet + \chi}(X,E)$, hence a [[section]] of the [[associated ∞-bundle|associated]] [[(∞,1)-line bundle]]. \end{enumerate} If we consider the [[internal hom]] instead of the external [[(∞,1)-categorical hom space]] then things work even more nicely and we can use just $X$ instead of $X \times \mathbb{S}$: \begin{prop} \label{MappingSpectrumOutOfUnstableTypeAsCartesianInternalHom}\hypertarget{MappingSpectrumOutOfUnstableTypeAsCartesianInternalHom}{} For $X \in \mathbf{H} \stackrel{0}{\hookrightarrow} T \mathbf{H}$ a [[geometric homotopy type]] and $E \in Stab(\mathbf{H}) \simeq T_\ast \mathbf{H} \hookrightarrow T \mathbf{H}$ a [[spectrum object]], then the [[internal hom]]/[[mapping stack]] \begin{displaymath} [X,E]_{T \mathbf{H}} \in T \mathbf{H} \end{displaymath} (with respect to the Cartesian [[closed monoidal (∞,1)-category]] structure on the [[(∞,1)-topos]] is equivalently the [[mapping spectrum]] \begin{displaymath} [\Sigma^\infty X, E]_{Stab(\mathbf{H})} \in Stab(\mathbf{H}) \hookrightarrow T \mathbf{H} \,, \end{displaymath} in that \begin{displaymath} [X,E]_{T \mathbf{H}} \simeq [\Sigma^\infty X,E]_{Stab(\mathbf{H})} \,. \end{displaymath} \end{prop} \begin{proof} Notice that as an object of $T \mathbf{H} \hookrightarrow \mathbf{H}^{seq}$, the object $X$ is the constant [[(∞,1)-presheaf]] on $seq$. By the formula for the [[internal hom]] in an [[(∞,1)-category of (∞,1)-presheaves]] we have \begin{displaymath} [X,E]_\bullet \simeq \mathbf{H}^{seq}(X \times \bullet, E) \,. \end{displaymath} But since $X$ is constant the object $X \times \bullet$ is for each object of $seq$ the [[representable functor|presheaf represented]] by that object. Therefore by the [[(∞,1)-Yoneda lemma]] it follows that \begin{displaymath} [X,E]_\bullet \simeq [X,E_\bullet] \,. \end{displaymath} This is manifestly the same formula as for the [[mapping spectrum]] out of $\Sigma^\infty X$. \end{proof} Similar kind of arguments give the following more general statement. \begin{prop} \label{}\hypertarget{}{} For $X \in \mathbf{H} \stackrel{0}{\hookrightarrow} T \mathbf{H}$ a [[geometric homotopy type]], for $E \in E_\infty(\mathbf{H})$ an [[E-∞ ring]] with $(\widehat{Pic(E)} \to Pic(E)) \hookrightarrow T \mathbf{H}$ its universal [[(∞,1)-line bundle]] over its [[Picard ∞-groupoid]], then the [[internal hom]]/[[mapping stack]] \begin{displaymath} [X,\widehat{Pic(E)}]_{T \mathbf{H}} \in T \mathbf{H} \end{displaymath} is the object whose \begin{itemize}% \item base homotopy type is the [[E-∞ ring]] $[X, Pic(E)]$ of $E$-[[twisted cohomology|twist]] on $X$; \item whose [[spectrum bundle]] is the collection of $\chi$-[[twisted cohomology|twisted E-cohomology spectra]] for all twists $\chi$. \end{itemize} \end{prop} In full generality we may formulate the [[internal hom]] [[mapping space]] in $T \mathbf{H}$ in [[homotopy type theory]] notation as follows. \begin{prop} \label{InternalHomGeneral}\hypertarget{InternalHomGeneral}{} For \begin{displaymath} (a \colon A) \;\vdash\; E_a \colon Spectra(\mathbf{H}) \end{displaymath} and \begin{displaymath} (b \colon B) \;\vdash\; F_b \colon Spectra(\mathbf{H}) \end{displaymath} two [[spectrum bundle]] [[dependent type|dependent types]] over base [[homotopy types]], $A,B \colon \mathbf{H}$, respectively, then the [[function type]] $(E \to F) \colon T\mathbf{H}$ between them (regarded as [[homotopy types]] in $T \mathbf{H}$) is \begin{displaymath} \chi \colon (A \to B); \sigma \colon \underset{a \colon A}{\prod} SpMap(E_a,F_{\chi(a)}) \;\vdash\; \underset{a \colon A}{\prod} F_{\chi(a)} \,. \end{displaymath} \end{prop} \begin{proof} Let $(x:X)\vdash M_x : Spectra$ be another [[spectrum bundle]]. The [[cartesian product]] $M\times E$ in $T \mathbf{H}$ is then $(x:X),(a:A) \vdash M_x \oplus E_a$, with $\oplus$ also the [[coproduct]] (hence the [[direct sum]]), since [[spectra]] are [[stable (infinity,1)-category|stable]] and hence [[additive (infinity,1)-category|additive]]. We compute the [[mapping space]] $T\mathbf{H}(M\times E,F)$ as follows: \begin{displaymath} \begin{aligned} \sum_{(\phi:X\times A \to B)} \prod_{((x,a):X\times A)} SpMap(M_x\oplus E_a,F_{\phi(x,a)}) &=& \sum_{(\phi:X \to A \to B)} \prod_{(x:X)} \prod_{(a:A)} SpMap(E_a,F_{\phi(x,a)}) \times SpMap(M_x,F_{\phi(x,a)})\\ &=& \prod_{(x:X)} \sum_{(\chi:A \to B)} \left(\prod_{(a:A)} SpMap(E_a,F_{\chi(a)})\right) \times \left( \prod_{(a:A)} SpMap(M_x,F_{\chi(a)}) \right)\\ &=& \prod_{(x:X)} \sum_{\psi : \sum_{(\chi:A \to B)} \prod_{(a:A)} SpMap(E_a,F_{\chi(a)})} SpMap\left(M_x, \prod_{(a:A)} F_{pr_1(\psi)(a)}\right)\\ &=& \sum_{\rho : X \to \sum_{(\chi:A \to B)} \prod_{(a:A)} SpMap(E_a,F_{\chi(a)})} \prod_{(x:A)} SpMap\left(M_x, \prod_{(a:A)} F_{pr_1(\rho(x))(a)}\right) \end{aligned} \end{displaymath} In the first line, we [[currying|curry]] $\phi$, apply the [[induction principle]] for [[dependent type|dependent]] maps out of $X\times A$, and also apply the [[universal property]] of the [[coproduct]] $M_x \oplus E_a$. In the second line, we apply the [[universal property]] for mapping into [[∞-types]] (the ``[[type-theoretic axiom of choice]]'') and also that for dependent functions into a [[Cartesian product|product]]. In the third line we apply the associativity of [[∞-types]], and also the [[universal property]] for mapping into the [[dependent product]] $\prod$ of [[spectra]]. Finally, in the fourth line, we apply the [[type-theoretic axiom of choice]] again in the other direction. The resulting [[type]] is the [[mapping space]] from $M$ to the claimed [[function type]] $(E\to F)$ defined above. (See also \href{http://nforum.mathforge.org/discussion/5321/parameterized-cohesive-spectra/?Focus=42394#Comment_42394}{this discussion}.) \end{proof} \begin{example} \label{}\hypertarget{}{} We have the following special cases of prop. \ref{InternalHomGeneral}. \begin{enumerate}% \item If $E_a = 0$ for all $a \colon A$, and if $B = \ast$, then the function type is \begin{displaymath} \vdash \; \underset{a \colon A}{\prod} F \end{displaymath} which reproduces the [[mapping spectrum]] $SpMap(\Sigma^\infty A, F)$ from prop. \ref{MappingSpectrumOutOfUnstableTypeAsCartesianInternalHom}. \item If $A = B = \ast$ then the mapping type is \begin{displaymath} \sigma \colon SpMap(E,F) \;\vdash \; F \colon Spectra \end{displaymath} \item If $E_a = 0$ for all $a \colon A$ and $F_b = 0$ for all $b \colon B$ then the mapping type is \begin{displaymath} \chi \colon (A \to B)\;\vdash \; 0 \colon Spectra \,. \end{displaymath} \end{enumerate} \end{example} \hypertarget{CohesiveAndDifferentialRefinement}{}\subsubsection*{{Cohesive and differential refinement}}\label{CohesiveAndDifferentialRefinement} Let $T\mathbf{H}$ be a tangent cohesive $(\infty,1)$-topos and write $T_\ast \mathbf{H}$ for the [[stable (∞,1)-category]] of [[spectrum objects]] inside it. We discuss how every [[stable homotopy type]] here canonically sits in the middle of a \emph{[[differential cohomology diagram]]}. \begin{prop} \label{}\hypertarget{}{} For every $A \in T_\ast \mathbf{H}$ the [[natural transformation|naturality square]] \begin{displaymath} \itexarray{ A &\stackrel{}{\longrightarrow}& A/\flat A \\ \downarrow &{}^{(pb)}& \downarrow \\ \Pi(A) &\stackrel{}{\longrightarrow}& \Pi(A/\flat A) } \end{displaymath} (of the [[shape modality]] applied to the [[homotopy cofiber]] of the [[counit of a comonad|counit]] of the [[flat modality]]) is an [[(∞,1)-pullback]] square. \end{prop} This was observed in (\hyperlink{BunkeNikolausVoelkl13}{Bunke-Nikolaus-V\"o{}lkl 13}). It is an incarnation of a [[fracture theorem]]. \begin{proof} By [[cohesive (infinity,1)-topos|cohesion]] and [[stable (infinity,1)-category|stability]] we have the diagram \begin{displaymath} \itexarray{ \flat A &\longrightarrow & A &\stackrel{}{\longrightarrow}& A/\flat A \\ \downarrow^{\mathrlap{\simeq}} && \downarrow && \downarrow \\ \Pi(\flat A) &\longrightarrow& \Pi(A) &\stackrel{}{\longrightarrow}& \Pi(A/\flat A) } \end{displaymath} where both rows are [[homotopy fiber sequences]]. By [[cohesive (infinity,1)-topos|cohesion]] the left vertical map is an [[equivalence in an (infinity,1)-category|equivalence]]. The claim now follows with the \href{homotopy+pullback#HomotopyFiberCharacterization}{homotopy fiber characterization} of [[homotopy pullbacks]]. \end{proof} \begin{remark} \label{}\hypertarget{}{} This means that in stable cohesion every cohesive stable homotopy type is in controled sense a cohesive extension/refinement of its [[geometric realization of cohesive infinity-groupoids|geometric realization]] [[discrete infinity-groupoid|geometrically discrete]] (``bare'') stable [[homotopy type]] by the non-[[discrete object|discrete]] part of its cohesive structure; In particular, $A/\flat A$ may be identified with differential cycle data. Indeed, by stability and cohesion it is the \href{cohesive+%28infinity,1%29-topos+--+structures#deRhamCohomology}{flat de Rham coefficient object} \begin{displaymath} A/\flat A = \flat_{dR}\Sigma A \end{displaymath} of the [[suspension]] of $A$, and the map to this quotient is thus the [[Maurer-Cartan form]] $\theta_A$. So \begin{displaymath} \itexarray{ A &\stackrel{\theta_A}{\longrightarrow}& \flat_{dR}\Sigma A \\ \downarrow &{}^{(pb)}& \downarrow \\ \Pi(A) &\stackrel{}{\longrightarrow}& \Pi(A/\flat A) } \end{displaymath} exhibits $A$ as a [[differential cohomology]]-coefficient of the [[generalized cohomology theory]] $\Pi(A)$. It follows by the discussion at [[schreiber:differential cohomology in a cohesive topos]] that the further differential refinement $\widehat{A}$ of $A$ should be given by a further [[homotopy pullback]] \begin{displaymath} \itexarray{ \widehat{A} &\longrightarrow& \Omega^1(-,Lie(A)) \\ \downarrow &{}^{(pb)}& \downarrow \\ A &\stackrel{\theta_A}{\longrightarrow}& \flat_{dR}\Sigma A \\ \downarrow &{}^{(pb)}& \downarrow \\ \Pi(A) &\stackrel{}{\longrightarrow}& \Pi(A/\flat A) } \,. \end{displaymath} But of course by the generality of the above proposition, such an $\widehat{A}$ sits itself again in its fracture-like pullback diagram. \end{remark} Dually: \begin{prop} \label{}\hypertarget{}{} For every $A \in T_\ast \mathbf{H}$ the [[natural transformation|naturality square]] \begin{displaymath} \itexarray{ \flat(\Pi_{dR} \Sigma^{-1} A) &\longrightarrow & \Pi_{dR}(\Sigma^{-1} A) \\ \downarrow && \downarrow \\ \flat A &\stackrel{}{\longrightarrow}& A } \end{displaymath} (of the [[flat modality]] applied to the [[homotopy fiber]] of the [[unit of a monad|unit]] of the [[shape modality]]) is an [[(∞,1)-pullback]] square. \end{prop} \begin{proof} As before but dually, the diagram extends to a morphism of [[homotopy cofiber]] diagrams of the form \begin{displaymath} \itexarray{ \flat(\Pi_{dR} \Sigma^{-1} A) &\longrightarrow & \Pi_{dR}(\Omega A) \\ \downarrow && \downarrow \\ \flat A &\stackrel{}{\longrightarrow}& A \\ \downarrow && \downarrow \\ \flat \Pi(A) &\stackrel{\simeq}{\longrightarrow}& \Pi(A) } \,, \end{displaymath} and by [[cohesion]] the bottom horizontal morphism is an [[equivalence in an (infinity,1)-category|equivalence]]. \end{proof} Combining these two statements yields the following (\hyperlink{BunkeNikolausVoelkl13}{Bunke-Nikolaus-V\"o{}lkl 13}). \begin{cor} \label{TheDifferentialDiagram}\hypertarget{TheDifferentialDiagram}{} For $\mathbf{H}$ a [[cohesive (∞,1)-topos]] every [[stable homotopy type]] $A \in Stab(\mathbf{H}) \hookrightarrow T \mathbf{H}$ sits inside a [[diagram]] of the form \begin{displaymath} \itexarray{ && \Pi_{dR} \Omega A && \longrightarrow && \flat_{dR}\Sigma A \\ & \nearrow & & \searrow & & \nearrow_{\mathrlap{\theta_A}} && \searrow \\ \flat \Pi_{dR} \Omega A && && A && && \Pi \flat_{dR}\Sigma A \\ & \searrow & & \nearrow & & \searrow && \nearrow_{\mathrlap{\Pi \theta_A}} \\ && \flat A && \longrightarrow && \Pi A } \,, \end{displaymath} where the two squares are [[homotopy pullback]] squares and the two diagonals are the [[fiber sequences]] of the [[Maurer-Cartan form]] $\theta_A$ and its dual. \end{cor} \begin{remark} \label{}\hypertarget{}{} The bottom horizontal morphisms in the diagram in prop. \ref{TheDifferentialDiagram} are the canonical \href{cohesive%20topos#CanonicalComparison}{points-to-pieces transform}. \end{remark} \begin{remark} \label{}\hypertarget{}{} This kind of diagram under forming $\pi_0$ has been traditionally known from [[ordinary differential cohomology]] and from [[differential K-theory]], and had been used in proposals to axiomatize [[differential cohomology]], see for instance (\href{http://arxiv.org/abs/1208.3961}{Bunke 12, prop. 4.57}) and see at \emph{[[differential cohomology diagram]]}. Here we see that this holds fully generally for every stable cohesive homotopy type. If one still regards this diagram as characteristic of ``differential'' refinement it hence exhibits every cohesive stable type as a [[coefficients]] of \emph{some} [[differential cohomology]] theory. This is a strong version of the synthetic notion ``[[schreiber:differential cohomology in a cohesive topos]]'' . For more on this see also at \emph{[[smooth spectrum]]}. \end{remark} \hypertarget{related_concepts}{}\subsection*{{Related concepts}}\label{related_concepts} \begin{itemize}% \item [[sheaf of spectra]] \item [[smooth spectrum]] \item [[twisted generalized cohomology]] \item [[twisted bivariant cohomology]] \item [[twisted differential cohomology]] \item [[twisted smooth cohomology in string theory]] \end{itemize} \hypertarget{references}{}\subsection*{{References}}\label{references} The idea of forming $T_\ast \mathbf{H}$ as a home for nontrivial [[stable homotopy types]] was originally suggested by [[Georg Biedermann]] and [[André Joyal]], see section 35 of \begin{itemize}% \item [[André Joyal]], \emph{Notes on Logoi}, 2008 (\href{http://www.math.uchicago.edu/~may/IMA/JOYAL/Joyal.pdf}{pdf}) \end{itemize} and see the further references at \emph{[[tangent (infinity,1)-topos]]}. Discussion of [[differential cohomology]] in $T_\ast Smooth \infty Grpd \simeq Stab(Smooth \infty Grpd)$ is in \begin{itemize}% \item [[Ulrich Bunke]], [[Thomas Nikolaus]], [[Michael Völkl]], \emph{Differential cohomology theories as sheaves of spectra} (\href{http://arxiv.org/abs/1311.3188}{arXiv:1311.3188}) \end{itemize} For details see at \emph{[[differential cohomology hexagon]]}. The above discussion of geometric twisted generalized cohomology as cohomology in the tangent cohesive $\infty$-topos was presented in \begin{itemize}% \item [[Urs Schreiber]], talk at \emph{\href{http://wwwmath.uni-muenster.de/sfb/sfb878/2013/twists.html}{Twists, generalised cohomology and applications}}, October 2013 (\href{twisted+smooth+cohomology+in+string+theory#LocalPrequantumFieldTheory}{talk notes}) \end{itemize} Discussion in a comprehensive context of cohesion is in section 4.2.3 of \begin{itemize}% \item [[Urs Schreiber]], \emph{[[schreiber:differential cohomology in a cohesive topos]]} (\href{http://arxiv.org/abs/1310.7930}{arXiv:1310.7930}) \end{itemize} [[!redirects cohesive tangent (∞,1)-topos]] [[!redirects stable cohesive homotopy theory]] [[!redirects stable cohesive homotopy type theory]] [[!redirects cohesive stable homotopy theory]] [[!redirects cohesive stable homotopy type theory]] [[!redirects tangent cohesion]] [[!redirects stable cohesion]] [[!redirects tangent cohesive ∞-topos]] [[!redirects tangent cohesive ∞-toposes]] [[!redirects tangent cohesive infinity-topos]] [[!redirects tangent cohesive infinity-toposes]] \end{document}