Výsledky vyhledávání - "Andretta, A."

Report

First Solar Orbiter observation of a dark halo in the solar atmosphere

Autor: Lezzi, Serena Maria, Long, David M., Andretta, Vincenzo, Baker, Deborah, Dolliou, Antoine, Murabito, Mariarita, Parenti, Susanna, Prado, Natalia Zambrana

Publikováno v: A&A 690, A342 (2024)

Solar active regions (ARs) are often surrounded by dark large areas of reduced emission compared to the quiet Sun, observed at various wavelengths corresponding to chromosphere, transition region (TR) and corona, and known as Dark Halos (DHs). DHs ha

Externí odkaz: http://arxiv.org/abs/2408.17172

Zobrazit plný text záznamu

Report

The breadth of constructibility degrees and definable Sierpi\'nski's coverings

Autor: Andretta, Alessandro, Notaro, Lorenzo

Generalizing a result of T\"ornquist and Weiss, we study the connection between the existence of $\varSigma_2^1$ Sierpi\'{n}ski's coverings of $\mathbb{R}^n$, and a cardinal invariant of the upper semi-lattice of constructibility degrees known as bre

Externí odkaz: http://arxiv.org/abs/2408.10182

Zobrazit plný text záznamu

Report

How many sprays cover the space?

Autor: Andretta, Alessandro, Izmestiev, Ivan

For all $d \geq 3$ we show that the cardinality of $ \mathbb{R} $ is at most $\aleph_n $ if and only if $ \mathbb{R}^d $ can be covered with $ ( n + 1 ) ( d - 1 ) + 1 $ sprays whose centers are in general position in a hyperplane. This extends previo

Externí odkaz: http://arxiv.org/abs/2406.04078

Zobrazit plný text záznamu