пишут что иногда в ряд R,C,H,O,... между кватернионами H и октонионами O уместно добавить шестимерную алгебру секстонионов S (определение на картинке; U=R^2).
Например, можно определить проективную плоскость SP^2 — 12-мерное вещественное алгебраическое многообразие. Особые точки образуют RP^5, их дополнение — векторное расслоение ранга 4 над Gr(2,R^6). (а проективная прямая SP^1 — особая квадрика в RP^7)
А ещё так можно построить (не простую) алгебру Ли e_{7.5}, которая сидит между (исключительными простыми) алгебрами Ли e_7 и e_8 https://arxiv.org/abs/math/0402157
пишут что иногда в ряд R,C,H,O,... между кватернионами H и октонионами O уместно добавить шестимерную алгебру секстонионов S (определение на картинке; U=R^2).
Например, можно определить проективную плоскость SP^2 — 12-мерное вещественное алгебраическое многообразие. Особые точки образуют RP^5, их дополнение — векторное расслоение ранга 4 над Gr(2,R^6). (а проективная прямая SP^1 — особая квадрика в RP^7)
А ещё так можно построить (не простую) алгебру Ли e_{7.5}, которая сидит между (исключительными простыми) алгебрами Ли e_7 и e_8 https://arxiv.org/abs/math/0402157
Asked about its stance on disinformation, Telegram spokesperson Remi Vaughn told AFP: "As noted by our CEO, the sheer volume of information being shared on channels makes it extremely difficult to verify, so it's important that users double-check what they read." Sebi said data, emails and other documents are being retrieved from the seized devices and detailed investigation is in progress. "There is a significant risk of insider threat or hacking of Telegram systems that could expose all of these chats to the Russian government," said Eva Galperin with the Electronic Frontier Foundation, which has called for Telegram to improve its privacy practices. At this point, however, Durov had already been working on Telegram with his brother, and further planned a mobile-first social network with an explicit focus on anti-censorship. Later in April, he told TechCrunch that he had left Russia and had “no plans to go back,” saying that the nation was currently “incompatible with internet business at the moment.” He added later that he was looking for a country that matched his libertarian ideals to base his next startup. Telegram was co-founded by Pavel and Nikolai Durov, the brothers who had previously created VKontakte. VK is Russia’s equivalent of Facebook, a social network used for public and private messaging, audio and video sharing as well as online gaming. In January, SimpleWeb reported that VK was Russia’s fourth most-visited website, after Yandex, YouTube and Google’s Russian-language homepage. In 2016, Forbes’ Michael Solomon described Pavel Durov (pictured, below) as the “Mark Zuckerberg of Russia.”
from ua
