Combinatorics of tropical Hurwitz cycles

We study properties of the tropical double Hurwitz loci defined by Bertram, Cavalieri and Markwig. We show that all such loci are connected in codimension one. If we mark preimages of simple ramification points, then for a generic choice of such points the resulting cycles are weakly irreducible, i.e. an integer multiple of an irreducible cycle. We study how Hurwitz cycles can be written as divisors of rational functions and show that they are numerically equivalent to a tropical version of a representation as a sum of boundary divisors. The results and counterexamples in this paper were obtained with the help of a-tint, an extension for polymake for tropical intersection theory.Comment: 29 pages, 16 figures. Minor revisions, to appear in Journal of Algebraic Combinatoric

Russula vinosoflavescens sp. nov., from deciduous forests of Northern Alsace, France

Based on morphological, molecular, and ecological data, a new species of Russula sect. Russula, found on several occasions under deciduous trees in Northern Alsace is described and illustrated as: Russula vinosoflavescens, belonging to R. subsect. Sardoninae

Moduli spaces of rational weighted stable curves and tropical geometry

We study moduli spaces of rational weighted stable tropical curves, and their connections with the classical Hassett spaces. Given a vector w of weights, the moduli space of tropical w-stable curves can be given the structure of a balanced fan if and only if w has only heavy and light entries. In this case, we can express the moduli space as the Bergman fan of a graphic matroid. Furthermore, we realize the tropical moduli space as a geometric tropicalization, and as a Berkovich skeleton, of the classical moduli space. This builds on previous work of Tevelev, Gibney--Maclagan, and Abramovich--Caporaso--Payne. Finally, we construct the moduli spaces of heavy/light weighted tropical curves as fiber products of unweighted spaces, and explore parallels with the algebraic world.Comment: 26 pages, 8 TikZ figures. v3: Minor changes and corrections. Final version to appear in Forum of Mathematics, Sigm

Rationality as the Therapy of Self-Liberation in Spinoza's Ethics

A given statement may be plausible, well founded or true. An individual action may be judged courageous, useful or good. Human beings are judged as well, for statements or actions that invite such evaluations, though the terms used may be different: a person may be described as truthful and virtuous, clever and happy. Epistemology and ethics - the theories that justify theoretical and practical judgements - may address not only the criteria used to assess states of belief, assertions, knowledge and the like, actions, omissions and feelings, but also the people that give rise to them. Nowadays, the issue of when and how a human being becomes clever, truthful, good or happy is less a matter of philosophy and more a question for religion, psychology and pedagogy. This has not always been the case. There has been a perceptible shift in moral philosophy: in antiquity, inquiries as to when a life is to be classified as good or happy were prevalent; in the modern era, the focus is primarily on when an individual action is to be regarded as right or good, wrong or ba

Visita de los indios originarios y forasteros de Paucarcolla en 1728.

Sin resume

Bernardo Monteagudo y su intervención en el proyecto monárquico para el Perú

Bernardo Monteagudo fue uno de los miembros más destacados de aquella primera generación de políticos apasionados por el poder que surgieron en América hispana al fragor de las guerras de Independencia. Su inteligencia superior, su excepcional cultura, su lealtad a la causa americana, así como su carácter, constancia, don de mando e ilimitada capacidad de trabajo y organización, unidos a un pragmatismo poco común, le convirtieron en el revolucionario por excelencia. El zigzagueante sendero ideológico que lo condujo desde ese jacobinismo extremo con el cual azuzó a los porteños en la Revolución de Mayo hasta el monarquismo sui generis que promovió desde el Ministerio de Guerra y Marina y la Sociedad Patriótica en Lima, da cuenta de la inventiva del pensamiento revolucionario y de su recomposición en función de problemáticas concretas. .Fil: Hampe Martínez, Teodoro