Roberto Gualtieri

Roberto Gualtieri is not mentioned in any of the provided news articles. The articles focus on events happening in Rome, such as the public viewing for fashion designer Valentino Garavani, the introduction of a €2 fee for tourists to access the area around the Trevi Fountain, and the opening of new subway stops that showcase ancient Roman artifacts. Without any mention of Gualtieri, it's impossible to determine his role, background, or relevance to these events. Therefore, I cannot provide a summary about him based on the given information.