Cartas de Joaquim de Carvalho a Alfredo Pimenta: 1922-36

Personalidades e credos, filosofias e ideias, convicções e razões, tudo parecia conspirar para o perfeito desentendimento entre estes dois autores: porém, ao longo de quinze anos, não foi bem assim.Raros documentos, como os textos do scriptorium, dados ao póstumo estudo epistolográfico, arquivam a fresca energia da autenticidade e a aura do instante, mesmo se já mediadas por releituras e reflexões sobre o que se acabou de escrever; e raros documentos catalogam com tanta precisão os rastos inscritos, possibilitando a legibilidade interna e a reconstrução mais rigorosa de uma hermenêuticos de teor intelectual, psicológico e biográfico.Para o leitor mais treinado ou para o especialista, o traço, o meandro cursivo da letra, a in-tensão do rasgo no papel, hesitações e lapsos calami, são vestígios gestuais daquilo mesmo que o próprio Joaquim de Carvalho se apercebeu, com Dilthey, serem indícios do Einfühlung, que assinalam a (in)esperada entrada nesse mundo virtual do outro, no imo do universo de representações de um autor. Quer dizer: pelo exame do sym-pathos se acede, também, ao portal da sua egohistória

Quasiparticle picture from the Bekenstein bound

We provide general arguments regarding the connection between low-energy theories (gravity and quantum field theory) and a hypothetical fundamental theory of quantum gravity, under the assumptions of (i) validity of the holographic bound and (ii) preservation of unitary evolution at the level of the fundamental theory. In particular, the appeal to the holographic bound imposed on generic physical systems by the Bekenstein-Hawking entropy implies that both classical geometry and quantum fields propagating on it should be regarded as phenomena emergent from the dynamics of the fundamental theory. The reshuffling of the fundamental degrees of freedom during the unitary evolution then leads to an entanglement between geometry and quantum fields. The consequences of such scenario are considered in the context of black hole evaporation and the related information-loss issue: we provide a simplistic toy model in which an average loss of information is obtained as a consequence of the geometry-field entanglement.Comment: 11 pages, 1 figure, Corfu Summer Institute 2017 'School and Workshops on Elementary Particle Physics and Gravity', 2-28 September 2017, Corfu, Greec

A unified approach to linear probing hashing with buckets

We give a unified analysis of linear probing hashing with a general bucket size. We use both a combinatorial approach, giving exact formulas for generating functions, and a probabilistic approach, giving simple derivations of asymptotic results. Both approaches complement nicely, and give a good insight in the relation between linear probing and random walks. A key methodological contribution, at the core of Analytic Combinatorics, is the use of the symbolic method (based on q-calculus) to directly derive the generating functions to analyze.Comment: 49 page