Black Composite M-branes

We generalise all the known supersymmetric composite M-branes to the corresponding black configurations. Thermodynamical formulae is written by using the simple rules to construct these black branes.Comment: 14 pages, latex. Revised version to appear in Nuclear Physics

Forbidden Configurations: Finding the number predicted by the Anstee-Sali Conjecture is NP-hard

Let F be a hypergraph and let forb(m,F) denote the maximum number of edges a hypergraph with m vertices can have if it doesn't contain F as a subhypergraph. A conjecture of Anstee and Sali predicts the asymptotic behaviour of forb(m,F) for fixed F. In this paper we prove that even finding this predicted asymptotic behaviour is an NP-hard problem, meaning that if the Anstee-Sali conjecture were true, finding the asymptotics of forb(m,F) would be NP-hard

Cruise Report 62S5,62S6, 62M1, 62M2 - Abalone

(PDF contains 6 pages.

Spherical CR Dehn Surgery

Consider a three dimensional cusped spherical $\mathrm{CR}$ manifold $M$ and suppose that the holonomy representation of $\pi_1(M)$ can be deformed in such a way that the peripheral holonomy is generated by a non-parabolic element. We prove that, in this case, there is a spherical $\mathrm{CR}$ structure on some Dehn surgeries of $M$. The result is very similar to R. Schwartz's spherical $\mathrm{CR}$ Dehn surgery theorem, but has weaker hypotheses and does not give the unifomizability of the structure. We apply our theorem in the case of the Deraux-Falbel structure on the Figure Eight knot complement and obtain spherical $\mathrm{CR}$ structures on all Dehn surgeries of slope $-3 + r$ for $r \in \mathbb{Q}^{+}$ small enough.Comment: 27 page

New species of Glossosomatidae from Bolivia with new records from Bolivia and northwestern Argentina (Trichoptera: Glossosomatidae)

Seven new species of Glossosomatidae are described from Bolivia. The seven new Bolivian species are: Mexitrichia collegarum n. sp., M. eduardoi n. sp., M. marini n. sp, M. usseglioi n. sp, Protoptila alumnorum n. sp, P. goitiai n. sp and P. myriamae n. sp. 18 species are recorded at the moment from Bolivia and northwestern Argentina: Merionoptila wigodzinskyi, Mexitrichia albolineata, M. bolivica, M. pocita, M. punensis, M. simla, M. argentinica, M. paraenchrysa, M. wygodzinskii, Protoptila dubitans, P. misionensis and the seven new species. A list of species of Glossosomatidae from Bolivia and northwestern Argentina is provided with new distributional records.Fil: Rueda Martin, Paola Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; ArgentinaFil: Gibon, Francois Marie. Muséum National d'Histoire Naturelle; Franci

The isotropy lattice of a lifted action

We obtain an algorithmic construction of the isotropy lattice for a lifted action of a Lie group $G$ on $TM$ and $T^*M$ based only on the knowledge of $G$ and its action on $M$. Some applications to symplectic geometry are also shown.Comment: minor modification