Notas sobre el género Entoloma en el noroeste de la Península Ibérica (IV): Entoloma legionense, una nueva especie del subgénero Leptonia

Notes about the genus Entoloma in the Northwest of the Iberian Peninsula (IV): Entoloma legionense, a new species of subgenus Leptonia. A new species of the genus Entoloma, found in León (Northwest of the Iberian Peninsula) is described. Entoloma legionense, sp. nov. differs from the most affine taxa of the subgenus Leptonia by the following combination of characters: stipe partially green-blackish, cheilocystidia frequently thick-walled, a more diverse in forms that in the neighbouring taxa, presence of encrusting pigment in numerous hyphae, presence of caulobasidia and caulocystidia and fructification on rotten wood of beech.Notas sobre el género Entoloma en el Noroeste de la Península Ibérica (IV): Entoloma legionense, una nueva especie del subgénero Leptonia. Se describe una especie nueva del género Entoloma, encontrada en León (Noroeste de la Península Ibérica). Entoloma legionense, sp. nov. se diferencia de los taxones más próximos del subgénero Leptonia en el que se encuadra, por presentar la siguiente combinación de caracteres: estipe parcialmente verdenegruzco, queilocistidios frecuentemente de pared gruesa, con una mayor diversidad de formas respecto a los taxones más cercanos, presencia de pigmento incrustante en numerosas hifas, presencia de caulobasidios y caulocistidios y fructificación sobre madera de haya, en descomposición

Notas sobre el género Entoloma en el noroeste de la Península Ibérica (IV): Entoloma legionense, una nueva especie del subgénero Leptonia

Notes about the genus Entoloma in the Northwest of the Iberian Peninsula (IV): Entoloma legionense, a new species of subgenus Leptonia. A new species of the genus Entoloma, found in León (Northwest of the Iberian Peninsula) is described. Entoloma legionense, sp. nov. differs from the most affine taxa of the subgenus Leptonia by the following combination of characters: stipe partially green-blackish, cheilocystidia frequently thick-walled, a more diverse in forms that in the neighbouring taxa, presence of encrusting pigment in numerous hyphae, presence of caulobasidia and caulocystidia and fructification on rotten wood of beech.Notas sobre el género Entoloma en el Noroeste de la Península Ibérica (IV): Entoloma legionense, una nueva especie del subgénero Leptonia. Se describe una especie nueva del género Entoloma, encontrada en León (Noroeste de la Península Ibérica). Entoloma legionense, sp. nov. se diferencia de los taxones más próximos del subgénero Leptonia en el que se encuadra, por presentar la siguiente combinación de caracteres: estipe parcialmente verdenegruzco, queilocistidios frecuentemente de pared gruesa, con una mayor diversidad de formas respecto a los taxones más cercanos, presencia de pigmento incrustante en numerosas hifas, presencia de caulobasidios y caulocistidios y fructificación sobre madera de haya, en descomposición

Field theory simulation of Abelian-Higgs cosmic string cusps

We have performed a lattice field theory simulation of cusps in Abelian-Higgs cosmic strings. The results are in accord with the theory that the portion of the strings which overlaps near the cusp is released as radiation. The radius of the string cores which must touch to produce the evaporation is approximately $r = 1$ in natural units. In general, the modifications to the string shape due to the cusp may produce many cusps later in the evolution of a string loop, but these later cusps will be much smaller in magnitude and more closely resemble kinks.Comment: 9 pages, RevTeX, 13 figures with eps

Decay of flux vacua to nothing

We construct instanton solutions describing the decay of flux compactifications of a $6d$ gauge theory by generalizing the Kaluza-Klein bubble of nothing. The surface of the bubble is described by a smooth magnetically charged solitonic brane whose asymptotic flux is precisely that responsible for stabilizing the 4d compactification. We describe several instances of bubble geometries for the various vacua occurring in a $6d$ Einstein-Maxwell theory namely, AdS_4 x S^2, R^{1,3} x S^2, and dS_4 x S^2. Unlike conventional solutions, the bubbles of nothing introduced here occur where a {\em two}-sphere compactification manifold homogeneously degenerates.Comment: 31 pages, 15 figure

Bubbles from Nothing

Within the framework of flux compactifications, we construct an instanton describing the quantum creation of an open universe from nothing. The solution has many features in common with the smooth 6d bubble of nothing solutions discussed recently, where the spacetime is described by a 4d compactification of a 6d Einstein-Maxwell theory on S^2 stabilized by flux. The four-dimensional description of this instanton reduces to that of Hawking and Turok. The choice of parameters uniquely determines all future evolution, which we additionally find to be stable against bubble of nothing instabilities.Comment: 19 pages, 6 figure

Strings at the bottom of the deformed conifold

We present solutions of the equations of motion of macroscopic F and D strings extending along the non compact 4D sections of the conifold geometry and winding around the internal directions. The effect of the Goldstone modes associated with the position of the strings on the internal manifold can be seen as a current on the string that prevents it from collapsing and allows the possibility of static 4D loops. Its relevance in recent models of brane inflation is discussed.Comment: 9+1 page