Pushforwards of Measures on Real Varieties under Maps with Rational Singularities

TL;DR

This paper proves that under certain conditions, the pushforward of smooth measures on real algebraic varieties with rational singularities has a continuous density, extending previous p-adic results to the real case.

Contribution

It extends the known results about measure pushforwards with rational singularities from p-adic fields to real algebraic varieties.

Findings

Pushforward measures have continuous densities under specified conditions.

Extension of p-adic results to the archimedean (real) case.

Applicable to algebraic varieties with rational singularities.

Abstract

Let $X,Y$ be algebraic varieties defined over $\Bbb R$. Assume $Y$ is smooth and $X$ is Gorenstein. Suppose $\varphi:X\to Y$ is a flat $\Bbb R$-morphism such that all the fibers have rational singularities. We show that the pushforward of any smooth, compactly supported measure on $X$ has a continuous density with respect to any smooth measure with non-vanishing density on $Y$. This extends a result of Aizenbud and Avni from the $p$-adic case to the archimedean case.