# Calabi-Yau double coverings of Fano-Enriques threefolds

## TL;DR

This paper explores Calabi-Yau threefolds obtained as double coverings of Fano-Enriques threefolds with singularities, calculating their invariants and identifying new examples with Picard number one.

## Contribution

It introduces new Calabi-Yau threefolds arising from double coverings of Fano-Enriques threefolds with terminal cyclic quotient singularities.

## Key findings

- Calabi-Yau threefolds are obtained as double coverings of certain Fano-Enriques threefolds.
- Calculated invariants for these Calabi-Yau threefolds with Picard number one.
- All identified examples are novel in the context of Calabi-Yau geometry.

## Abstract

This note is a report on the observation that the Enriques-Fano threefolds with terminal cyclic quotient singularities admit Calabi-Yau threefolds as their double coverings. We calculate the invariants of those Calabi-Yau threefolds when the Picard number is one. It turns out that all of them are new examples.