Autor: Alejandro Rivero

Por lo que cuentan en su blog, CommonCrawl esta usando la «harmonic centrality» a la hora de dar un ranking de hostnames y websites explorados, y decidir cuales explorar a continuacion. Curiosamente con esa medida se cuela en el top 1000 el instituto de astrofisica de canarias. Domcop calculó un «open pagerank» a partir del…

Estoy un poco pasmado con las soluciones que ofrecen en este foro para dividir un trapecio en dos partes de areas proporcionales: Para dividir un triangulo, construyes otro proporcional via raiz de dos: https://trazoide.com/foro/viewtopic.php?p=3307#p3307 Y para dividir un trapecio, te aprovechas de la idea de que su area es la diferencia entre la de dos…

With the idea of Dubois-Violette about using a Jordan Algebra to build three generations of the standard model I had had the hope of finding our lost -4/3 quarks as part of the content of a 27 + 27 representation of E6.  Asuming this was to be interpreted as the «decoloured» part of the standard…

for E6 down to SU(6)xSU(2) 27 = (6, 2) + (15, 1) SU(6) ? SU(4)×SU(2)×U(1) 6 = (1, 2)(?2) + (4, 1)(1) 15 = (1, 1)(?4) + (4, 2)(?1) + (6, 1)(2) SU(6) ? SU(3)×SU(3)×U(1) 6 = (3, 1)(1) + (1, 3)(?1) 15 = (3, 1)(2) + (1, 3)(?2) + (3, 3)(0) SU(4) ? SU(3)×U(1)…

Today I have been reviewing the archives of my ancient advisor, LJ Boya, who is long absent due to health issues, and of course there are some folders on octonions.   An early attempt to use «octonion calculus» is as early as Pais 1961, but it seems that they became a source of inspiration for…