# An induced map between rationalized classifying spaces for fibrations

## TL;DR

This paper constructs a natural map between classifying spaces of fibrations induced by rationally weakly trivial maps, explores conditions for sections, and applies these to liftings of group actions and rational toral rank evaluations.

## Contribution

It introduces a strictly induced map between classifying spaces for fibrations via Sullivan models and analyzes its properties and applications.

## Key findings

- The induced map $a_f$ can admit a section under certain conditions.
- Obstruction classes for lifting classifying maps are characterized.
- Applications to liftings of $G$-actions and rational toral ranks are provided.

## Abstract

Let $B{ aut}_1X$ be the Dold-Lashof classifying space of orientable fibrations with fiber $X$. For a rationally weakly trivial map $f:X\to Y$, our strictly induced map $a_f: (Baut_1X)_0\to (Baut_1Y)_0$ induces a natural map from a $X_0$-fibration to a $Y_0$-fibration. It is given by a map between the differential graded Lie algebras of derivations of Sullivan models. We note some conditions that the map $a_f$ admits a section and note some relations with the Halperin conjecture. Furthermore we give the obstruction class for a lifting of a classifying map $h: B\to (Baut_1Y)_0$ and apply it for liftings of $G$-actions on $Y$ for a compact connected Lie group $G$ as the case of $B=BG$ and evaluating of rational toral ranks as $r_0(Y)\leq r_0(X)$.