48,517 research outputs found
The Politics of Abstract Art. Forma 1 and the Italian Communist Party
Este artÃculo examina el papel del grupo de artistas abstractos Forma 1 en relación con la polÃtica cultural del Partido Comunista Italiano durante la posguerra, como ejemplo de los intentos de superar la dicotomÃa establecida en Italia entre arte abstracto y realismo socialista y producir una alternativa a la confrontación entre ambos discursos estéticos. Mientras los artistas realistas socialistas subrayaban la necesidad de expresar contenidos polÃticos explÃcitos con un estilo que asegurase su máxima legibilidad para una audiencia de masas, los artistas de Forma 1 argumentaban que la abstracción significaba una crÃtica de la representación pictórica que podÃa contribuir a la crÃtica de la ideologÃa burguesa, armonizando de este modo el marxismo con los desarrollos artÃsticos más avanzados. El PCI, por su parte, basaba su polÃtica artÃstica en amplias alianzas de artistas e intelectuales antifascistas, que cada vez eran más difÃciles de mantener en el clima de creciente confrontación polÃtica y cultural que siguió a la II
Guerra Mundial
Twisted equivariant K-theory of compact Lie group actions with maximal rank isotropy
We consider twisted equivariant K--theory for actions of a compact Lie group
on a space where all the isotropy subgroups are connected and of
maximal rank. We show that the associated rational spectral sequence \`a la
Segal has a simple --term expressible as invariants under the Weyl group
of . Namely, if is a maximal torus of , they are invariants of the
-equivariant Bredon cohomology of the universal cover of with
suitable coefficients. In the case of the inertia stack this term
can be expressed using the cohomology of and algebraic invariants
associated to the Lie group and the twisting. A number of calculations are
provided. In particular, we recover the rational Verlinde algebra when
.Comment: To appear in Journal of Mathematical Physics. Some mistakes have been
corrected in Section
Serial coalgebras and their valued Gabriel quivers
We study serial coalgebras by means of their valued Gabriel quivers. In
particular, Hom-computable and representation-directed coalgebras are
characterized. The Auslander-Reiten quiver of a serial coalgebra is described.
Finally, a version of Eisenbud-Griffith theorem is proved, namely, every
subcoalgebra of a prime, hereditary and strictly quasi-finite coalgebra is
serial.Comment: 22 page
Equivariant K-theory of compact Lie group actions with maximal rank isotropy
Let G denote a compact connected Lie group with torsion-free fundamental
group acting on a compact space X such that all the isotropy subgroups are
connected subgroups of maximal rank. Let be a maximal torus with
Weyl group W. If the fixed-point set has the homotopy type of a finite
W-CW complex, we prove that the rationalized complex equivariant K-theory of X
is a free module over the representation ring of G. Given additional conditions
on the W-action on the fixed-point set we show that the equivariant
K-theory of X is free over R(G). We use this to provide computations for a
number of examples, including the ordered n-tuples of commuting elements in G
with the conjugation action.Comment: Accepted for publication by the Journal of Topolog
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