Gribov copies, avalanches and dynamic generation of a gluon mass

Analytic calculations in the infrared regime of nonabelian gauge theories are hampered by the presence of Gribov copies which results in some ambiguity in the gauge-fixing procedure. This problem shares strong similarities with the issue of finding the true ground state among a large number of metastable states, a typical situation in the field of statistical physics of disordered systems. Building on this analogy, we propose a new gauge-fixing procedure which, we argue, makes more explicit the influence of the Gribov copies. A 1-loop calculation shows that the dynamics of these copies can lead to the spontaneous generation of a gauge-dependent gluon mass.Comment: 5 pages, 1 figur

Two Orders of Things: Wittgenstein on Reasons and Causes

This paper situates Wittgenstein in what is known as the causalism/anti-causalism debate in the philosophy of mind and action and reconstructs his arguments to the effect that reasons are not a species of causes. On the one hand, the paper aims to reinvigorate the question of what these arguments are by offering a historical sketch of the debate showing that Wittgenstein's arguments were overshadowed by those of the people he influenced, and that he came to be seen as an anti-causalist for reasons that are in large part extraneous to his thought. On the other hand, the paper aims to recover the arguments scattered in Wittgenstein's own writings by detailing and defending three lines of argument distinguishing reasons from causes. The paper concludes that Wittgenstein's arguments differ from those of his immediate successors; that he anticipates current anti-psychologistic trends; and that he is perhaps closer to Davidson than historical dialectics suggest

Adaptive non-asymptotic confidence balls in density estimation

We build confidence balls for the common density $s$ of a real valued sample $X_1,...,X_n$. We use resampling methods to estimate the projection of $s$ onto finite dimensional linear spaces and a model selection procedure to choose an optimal approximation space. The covering property is ensured for all $n\geq2$ and the balls are adaptive over a collection of linear spaces

The Self-Effacing Functionality of Blame

This paper puts forward an account of blame combining two ideas that are usually set up against each other: that blame performs an important function, and that blame is justified by the moral reasons making people blameworthy rather than by its functionality. The paper argues that blame could not have developed in a purely instrumental form, and that its functionality itself demands that its functionality be effaced in favour of non-instrumental reasons for blame—its functionality is self-effacing. This notion is sharpened and it is shown how it offers an alternative to instrumentalist or consequentialist accounts of blame which preserves their animating insight while avoiding their weaknesses by recasting that insight in an explanatory role. This not only allows one to do better justice to the authority and autonomy of non-instrumental reasons for blame, but also reveals that autonomy to be a precondition of blame’s functionality. Unlike rival accounts, it also avoids the “alienation effect” that renders blame unstable under reflection by undercutting the authority of the moral reasons which enable it to perform its function in the first place. It instead yields a vindicatory explanation that strengthens our confidence in those moral reasons

Davidsonian Causalism and Wittgensteinian Anti-Causalism: A Rapprochement

A longstanding debate in the philosophy of action opposes causalists to anti-causalists. Causalists claim the authority of Davidson, who offered powerful arguments to the effect that intentional explanations must be causal explanations. Anti-causalists claim the authority of Wittgenstein, who offered equally powerful arguments to the effect that reasons cannot be causes. My aim in this paper is to achieve a rapprochement between Davidsonian causalists and Wittgensteinian anti-causalists by showing how both sides can agree that reasons are not causes, but that intentional explanations are causal explanations. To this end, I first defuse Davidson’s Challenge, an argument purporting to show that intentional explanations are best made sense of as being explanatory because reasons are causes. I argue that Wittgenstein furnishes anti-causalists with the means to resist this conclusion. I then argue that this leaves the Master Argument for the claim that intentional explanations are causal explanations, but that by distinguishing between a narrow and a wide conception of causal explanation, we can resolve the stalemate between Wittgensteinian anti-causalists impressed by the thought that reasons cannot be causes and Davidsonian causalists impressed by the thought that intentional explanations must be causal explanations