Abstract:
Kant desenvolveu três grandes concep es de natureza. Cada uma corresponde e é viabilizada em uma de suas Críticas. Na primeira Crítica, a natureza é o conjunto do conhecimento que nos é possibilitado através do entendimento e representa a natureza mecanico-causal. é a natureza da qual trata a ciência. Na segunda Crítica nos é evidenciada uma natureza que transcende nossa sensibilidade e é fruto da raz o que cria suas próprias leis. é a natureza uprassensível, que fundamenta a liberdade e o agir prático-ético. Na terceira Crítica é tratada a natureza organica que é, ao mesmo tempo, causa e efeito de si mesma e é viabilizada pelo entendimento intuitivo. As diferentes concep es de natureza s o formas diferenciadas de conhecimento, elaboradas a partir de princípios diversos. Todas, no entanto, s o legítimas e n o se excluem. Kant developed three major conceptions of nature. Each one is made possible by and corresponds to one of his Critiques. In the First Critique, nature is the ensemble of knowledge that is made possible through the understanding and represents the mechanical-causal nature. This is nature as it is dealt with by science. In the Second Critique we are presented a conception of nature that transcends our sensibility and results from reason as it creates its own laws. This is supersensible nature, as it grounds freedom and the practical-ethical actions. In the Third Critique we have organic nature, which is, at once, cause and effect of itself and is made possible by intuitive understanding. The different conceptions of nature are differentiated forms of knowledge, elaborated from diverse principles. And yet the three forms of nature are legitimate and do not exclude the other two.

Abstract:
A concep o de filosofia formulada por Adorno foi impulsionada principalmente pela sua rea o crítica a sistemas com pretens es totalitárias: nazismo, stalinismo e a sociedade produtora de mercadorias. A filosofia representa um refúgio para a liberdade diante dessas estruturas: ela dá voz ao n o-idêntico. A capacidade de subverter os ordenamentos conceituais e sociais é implícita ao próprio pensamento, que se articula na forma de constela es em devir. A aproxima o da dialética com o materialismo, concebido enquanto primazia do objeto, fortalece a filosofia na sua potencialidade crítica, na sua proximidade com a realidade e com a liberdade. Resulta daí uma filosofia renovada, simultaneamente aberta e comprometida com a verdade. A proposta deste artigo é apresentar a interdependência desses conceitos e apontar para a relevancia da concep o de filosofia que deles emerge. The philosophical conception formulated by Adorno was mainly driven forward by his critical reaction to systems with totalitarian pretensions, such as Nazism, Stalinism and the product manufacturing society. The philosophy represents a refuge for freedom facing these structures: it gives voice to the non-identical. The ability to subvert the conceptual and social order is implicit in the thought itself, which is expressed as constellations to come. The dialectic approach with materialism, as the primacy of the object, strengthens the philosophy in its critical potential, in its proximity to reality and freedom. The result is a renewed philosophy, both open and committed to the truth. The purpose of this paper is to show the interdependence of these concepts and point to the relevance of the philosophical concept that emerges from them.

Abstract:
RESUMO: Este texto é uma tradu o de um artigo de Alfred Schütz, The Stranger: Na Essay in Social Psychology, publicado originalmente no The American Journal of Sociology. Vol. XLIX, No 6 – 05/1944, p. 499-507.

Abstract:
We study the dynamics of an exactly solvable lattice model for inhomogeneous interface growth. The interface grows deterministically with constant velocity except along a defect line where the growth process is random. We obtain exact expressions for the average height and height fluctuations as functions of space and time for an initially flat interface. For a given defect strength there is a critical angle between the defect line and the growth direction above which a cusp in the interface develops. In the mapping to polymers in random media this is an example for the transverse Meissner effect. Fluctuations around the mean shape of the interface are Gaussian.

Abstract:
Stochastic reaction-diffusion processes may be presented in terms of integrable quantum chains and can be used to describe various biological and chemical systems. Exploiting the integrability of the models one finds in some cases good agreement between experimental and exact theoretical data. This is shown for the Rubinstein-Duke model for gel-electrophoresis of DNA, the asymmetric exclusion process as a model for the kinetics of biopolymerization and the coagulation-diffusion model for exciton dynamics on TMMC chains.

Abstract:
We show that the stochastic dynamics of a large class of one-dimensional interacting particle systems may be presented by integrable quantum spin Hamiltonians. Using the Bethe ansatz and similarity transformations this yields new exact results. In a complementary approach we generalize previous work and present a new description of these and other processes and the related quantum chains in terms of an operator algebra with quadratic relations. The full solution of the master equation of the process is thus turned into the problem of finding representations of this algebra. We find a two-dimensional time-dependent representation of the algebra for the symmetric exclusion process with open boundary conditions. We obtain new results on the dynamics of this system and on the eigenvectors and eigenvalues of the corresponding quantum spin chain, which is the isotropic Heisenberg ferromagnet with non-diagonal boundary fields.

Abstract:
Using the Bethe ansatz, we obtain the exact solution of the master equation for the totally asymmetric exclusion process on an infinite one-dimensional lattice. We derive explicit expressions for the conditional probabilities P(x_1, ... ,x_N;t|y_1, ... ,y_N;0) of finding N particles on lattice sites x_1, ... ,x_N at time t with initial occupation y_1, ... ,y_N at time t=0.

Abstract:
We study a 12-parameter stochastic process involving particles with two-site interaction and hard-core repulsion on a $d$-dimensional lattice. In this model, which includes the asymmetric exclusion process, contact processes and other processes, the stochastic variables are particle occupation numbers taking values $n_{\vec{x}}=0,1$. We show that on a 10-parameter submanifold the $k$-point equal-time correlation functions $\exval{n_{\vec{x}_1} \cdots n_{\vec{x}_k}}$ satisfy linear differential- difference equations involving no higher correlators. In particular, the average density $\exval{n_{\vec{x}}} $ satisfies an integrable diffusion-type equation. These properties are explained in terms of dual processes and various duality relations are derived. By defining the time evolution of the stochastic process in terms of a quantum Hamiltonian $H$, the model becomes equivalent to a lattice model in thermal equilibrium in $d+1$ dimensions. We show that the spectrum of $H$ is identical to the spectrum of the quantum Hamiltonian of a $d$-dimensional, anisotropic spin-1/2 Heisenberg model. In one dimension our results hint at some new algebraic structure behind the integrability of the system.