Lessons from arXiv's 30 years of information sharing.

Since the launch of arXiv 30 years ago, modes of information spread in society have changed dramatically - and not always for the better. Paul Ginsparg, who founded arXiv, discusses how academic experience with online preprints can still inform information sharing more generally.

Sensitivity of collective outcomes identifies pivotal components.

A social system is susceptible to perturbation when its collective properties depend sensitively on a few pivotal components. Using the information geometry of minimal models from statistical physics, we develop an approach to identify pivotal components to which coarse-grained, or aggregate, properties are sensitive. As an example, we introduce our approach on a reduced toy model with a median voter who always votes in the majority.

Preprint Déjà Vu.

Twenty‐five years ago, in August 1991, I spent a couple of afternoons at Los Alamos National Laboratory writing some simple software that enabled a small group of physicists to share drafts of their articles via automated email transactions with a central repository. Within a few years, the site migrated to the nascent WorldWideWeb as arXiv.org, and experienced both expansion in coverage and heavy growth in usage that continues to this day.

Patterns of text reuse in a scientific corpus.

We consider the incidence of text "reuse" by researchers via a systematic pairwise comparison of the text content of all articles deposited to arXiv.org from 1991 to 2012. We measure the global frequencies of three classes of text reuse and measure how chronic text reuse is distributed among authors in the dataset.

Non-Abelian braiding of lattice bosons.

We report on a numerical experiment in which we use time-dependent potentials to braid non-Abelian quasiparticles. We consider lattice bosons in a uniform magnetic field within the fractional quantum Hall regime, where ν, the ratio of particles to flux quanta, is near 1/2, 1, or 3/2. We introduce time-dependent potentials which move quasiparticle excitations around one another, explicitly simulating a braiding operation which could implement part of a gate in a quantum computation.

Mapping subsets of scholarly information.

We illustrate the use of machine learning techniques to analyze, structure, maintain, and evolve a large online corpus of academic literature. An emerging field of research can be identified as part of an existing corpus, permitting the implementation of a more coherent community structure for its practitioners.