Kerodon

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Example 11.3.0.9. Let $q: \operatorname{\mathcal{C}}\rightarrow \operatorname{\mathcal{D}}$ be a cartesian fibration of categories (Definition 5.0.0.3), so that the induced map $\operatorname{N}_{\bullet }(q): \operatorname{N}_{\bullet }(\operatorname{\mathcal{C}}) \rightarrow \operatorname{N}_{\bullet }(\operatorname{\mathcal{D}})$ is a cartesian fibration of $\infty $-categories (Example 5.1.4.2). Then the homotopy transport representation $\operatorname{hTr}_{\operatorname{N}_{\bullet }(q)}: \operatorname{\mathcal{D}}^{\operatorname{op}} \rightarrow \mathrm{h} \mathit{\operatorname{Cat}_{\infty }}$ is given by the composition

\[ \operatorname{\mathcal{D}}^{\operatorname{op}} \xrightarrow { \chi _{q} } \operatorname{Pith}(\mathbf{Cat}) \rightarrow \mathrm{h} \mathit{\operatorname{Cat}} \xrightarrow { \operatorname{N}_{\bullet } } \mathrm{h} \mathit{\operatorname{Cat}_{\infty }}. \]

Here $\chi _{q}$ denotes the transport representation of Construction 11.10.2.4 (with respect to any cleavage of the fibration $q$), the second functor is the truncation map of Remark 11.6.0.113, and $\operatorname{N}_{\bullet }$ is the fully faithful functor of Remark 4.5.1.3. Stated more informally, the homotopy transport representation $\operatorname{hTr}_{ \operatorname{N}_{\bullet }(q)}$ of Construction 5.2.5.7 can be obtained from the transport representation $\chi _{ \operatorname{N}_{\bullet }(q)}$ of Construction 11.10.2.4 by passing from the $2$-category $\mathbf{Cat}$ to its homotopy category.