Direct Interactions in Relativistic Statistical Mechanics

Directly interacting particles are considered in the multitime formalism of predictive relativistic mechanics. When the equations of motion leave a phase-space volume invariant, it turns out that the phase average of any first integral, covariantly defined as a flux across a $7n$-dimensional surface, is conserved. The Hamiltonian case is discussed, a class of simple models is exhibited, and a tentative definition of equilibrium is proposed.Comment: Plain Tex file, 26 page

Distribution of responsibility for climate change within the milieu

This article approaches the challenges of the distribution of responsibility for climate change on a local level using the framework of the milieu. It suggests that the framework of the milieu, inspired by Japanese and cross-cultural environmental philosophy, provides pathways to address the four challenges of climate change (global dispersion, fragmentation of agency, institu-tional inadequacy, temporal delay). The framework of the milieu clarifies the interrelations between the individual, the community, and the local milieu and is open to a conservative view of human communities and an inclusive view of multispecies communities. On this basis, an account of individual responsibility that is anchored in the local milieu and includes a responsibility to collaborate across milieus is developed. It consists of a forward-looking responsibility that balances a degree of contributory responsibility for one s imprints on the milieu with a degree of capacity-responsibility that varies regarding the individual s knowledge and powers, and the acceptability of practices within the local milieu. © 2021 by the author. Licensee MDPI, Basel, Switzerland.Swiss National Science Foundatio

Anthropocentrism as the scapegoat of the environmental crisis: a review

Anthropocentrism has been claimed to be the root of the global environmental crisis. Based on a multidisciplinary (e.g. environmental philosophy, animal ethics, anthro - pology, law) and multilingual (English, Spanish, French, German, Japanese) literature review, this article proposes a conceptual analysis of ‘anthropocentrism’ and reconstructs the often implicit argument that links anthropocentrism to the environmental crisis. The variety of usages of the concept of ‘anthropocentrism’ described in this article reveals many underlying disagreements under the apparent unanimity of the calls to reject anthropocentrism, both regarding what exactly is the root of the problem, and the nature of the possible solutions. It highlights the limitations of the argument of anthropocentrism as the scapegoat of the environmental crisis and identifies two main challenges faced by attempts to go beyond anthropocentrism: an epistemological challenge regarding knowledge and the place of sciences, and a metaethical challenge related to values and cultural pluralism. Beyond the issue of an anthropocentric point of view, the core of the problem might be an intertwinement of views and as sumptions that work together to undermine attempts to protect the environment from the greed of some humans, such as the human−nature dichotomy, capitalism, consumerism, industrialism, etc. Finally, this article suggests that making the nuances and the presuppositions that underlie various versions of the anti-anthropocentric rhetoric explicit is necessary to foster constructive dialogue among different anti-anthropocentrism proponents, as well as with their detractors. © The author 2022. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are un - restricted. Authors and original publication must be credited.This article greatly benefitted from constructive comments on previous versions by Unai Pascual, Bosco Lliso, Leila Chakroun, Luis Llored Alix, Romaric Jannel and Daniel Othenin-Girard, as well as by the 2 anonymous reviewers and by the editors of the Journal. This research was hosted by the Basque Center for Climate Change (BC3) and funded by a Swiss Science Foundation Grant No. P2SKP1_194948

Kinetics of ballistic annihilation and branching

We consider a one-dimensional model consisting of an assembly of two-velocity particles moving freely between collisions. When two particles meet, they instantaneously annihilate each other and disappear from the system. Moreover each moving particle can spontaneously generate an offspring having the same velocity as its mother with probability 1-q. This model is solved analytically in mean-field approximation and studied by numerical simulations. It is found that for q=1/2 the system exhibits a dynamical phase transition. For q<1/2, the slow dynamics of the system is governed by the coarsening of clusters of particles having the same velocities, while for q>1/2 the system relaxes rapidly towards its stationary state characterized by a distribution of small cluster sizes.Comment: 10 pages, 11 figures, uses multicol, epic, eepic and eepicemu. Also avaiable at http://mykonos.unige.ch/~rey/pubt.htm

Search for universality in one-dimensional ballistic annihilation kinetics

We study the kinetics of ballistic annihilation for a one-dimensional ideal gas with continuous velocity distribution. A dynamical scaling theory for the long time behavior of the system is derived. Its validity is supported by extensive numerical simulations for several velocity distributions. This leads us to the conjecture that all the continuous velocity distributions \phi(v) which are symmetric, regular and such that \phi(0) does not vanish, are attracted in the long time regime towards the same Gaussian distribution and thus belong to the same universality class. Moreover, it is found that the particle density decays as n(t)~t^{-\alpha}, with \alpha=0.785 +/- 0.005.Comment: 8 pages, needs multicol, epsf and revtex. 8 postscript figures included. Submitted to Phys. Rev. E. Also avaiable at http://mykonos.unige.ch/~rey/publi.html#Secon

Relativistic Corrections in a Three-Boson System of Equal Masses

Three-body systems of scalar bosons are described in the framework of relativistic constraint dynamics. With help of a change of variables followed by a change of wave function, two redundant degrees of freedom get eliminated and the mass-shell constraints can be reduced to a three-dimensional eigenvalue problem. In general, this problem is complicated, but for three equal masses a drastic simplification arises at the first post-Galilean order: the reduced wave equation becomes tractable, and we can compute a first-order correction beyond the nonrelativistic limit. The harmonic interaction is displayed as a toy model.Comment: 16 pages, no figure. Several points clarified, one typo corrected. References added. To appear in Physical Review

Gauging kinematical and internal symmetry groups for extended systems: the Galilean one-time and two-times harmonic oscillators

The possible external couplings of an extended non-relativistic classical system are characterized by gauging its maximal dynamical symmetry group at the center-of-mass. The Galilean one-time and two-times harmonic oscillators are exploited as models. The following remarkable results are then obtained: 1) a peculiar form of interaction of the system as a whole with the external gauge fields; 2) a modification of the dynamical part of the symmetry transformations, which is needed to take into account the alteration of the dynamics itself, induced by the {\it gauge} fields. In particular, the Yang-Mills fields associated to the internal rotations have the effect of modifying the time derivative of the internal variables in a scheme of minimal coupling (introduction of an internal covariant derivative); 3) given their dynamical effect, the Yang-Mills fields associated to the internal rotations apparently define a sort of Galilean spin connection, while the Yang-Mills fields associated to the quadrupole momentum and to the internal energy have the effect of introducing a sort of dynamically induced internal metric in the relative space.Comment: 32 pages, LaTex using the IOP preprint macro package (ioplppt.sty available at: http://www.iop.org/). The file is available at: http://www.fis.unipr.it/papers/1995.html The file is a uuencoded tar gzip file with the IOP preprint style include

Multilingualism for pluralising knowledge and decision making about people and nature relationships

The need for a pluralistic approach to biodiversity conservation science and policy is increasingly being recognized. We argue that plural perspectives require multilingualism in the sources and processes. Unless the linguistic bias and the related issues in terms of legitimacy and validity, resistance to inclusion, and knowledge coproduction are meaningfully addressed, biodiversity science and its positive effects for conservation policy and practices will necessarily be limited. We propose a series of options to address the linguistic biases in biodiversity conservation science and policy, including extending and tightening collaboration with environmental humanities scholars from diverse traditions as well as researchers from diverse linguistic contexts. We conclude by showing how multilingualism is especially relevant for cross-scale and global biodiversity governance. Read the free Plain Language Summary for this article on the Journal blog.This research was partially funded by Swiss National Science Foundation Grant No. P2SKP1_194948, and by Maria de Maeztu excellence accreditation 2023‐2026 (Ref. CEX2021‐001201‐M), funded by MCIN/AEI/10.13039/501100011033

Can the post-Newtonian gravitational waveform of an inspiraling binary be improved by solving the energy balance equation numerically?

The detection of gravitational waves from inspiraling compact binaries using matched filtering depends crucially on the availability of accurate template waveforms. We determine whether the accuracy of the templates' phasing can be improved by solving the post-Newtonian energy balance equation numerically, rather than (as is normally done) analytically within the post-Newtonian perturbative expansion. By specializing to the limit of a small mass ratio, we find evidence that there is no gain in accuracy.Comment: 13 pages, RevTeX, 5 figures included via eps

On the universality of a class of annihilation-coagulation models

A class of $d$-dimensional reaction-diffusion models interpolating continuously between the diffusion-coagulation and the diffusion-annihilation models is introduced. Exact relations among the observables of different models are established. For the one-dimensional case, it is shown how correlations in the initial state can lead to non-universal amplitudes for time-dependent particles density.Comment: 18 pages with no figures. Latex file using REVTE