Rasmus Kræmmer Rendsvig

This note describes code and experiments related to a Twitter dataset on the Danish National Election 2022, available at Harvard Dataverse (doi.org/10.7910/DVN/RWPZUN). We cluster Twitter users into bins of users that showed exactly the same liking/retweeting behavior over a month-long period during which the Danish National Election took place. To investigate whether any of these bins exhibited coordinated inauthentic behavior, we were interested in whether bin size correlated with user account deletions/suspensions and/or high bot scores from Botometer / Botometer Lite. We did not find significant correlations (also neither between Botometer and Botometer Lite scores). This note primarily contains the README.md from the GitHub repository LJ-9/Danish-Election-2022-Twitter-Likes-Retweets-Botscores-Inauthentic-Coordinated-Behavior of the same name, with a few additional comments and references. We upload the note for visibility, hoping that other researchers may find the data of use.

The paper introduces a broad family of metrics applicable to finite and countably infinite strings, or, by extension, to formal structures serving as semantics for countable languages. The main focus is on applications to sets of pointed Kripke models, a semantics for modal logics. For the resulting metric spaces, the paper classifies topological properties including which metrics are topologically equivalent, providing sufficient conditions for compactness, characterizing clopen sets and isolated points, and characterizing the metrical topologies by a concept of logical convergence. We then apply the approach to maps from dynamic epistemic logic, showing that product updates with action models yield continuous maps, hence allowing for an interpretation of the iterated updates as discrete time dynamical systems.

Logics for social networks have been studied in the recent literature. This paper presents a framework based on dynamic term-modal logic (⁠|$\textsf {DTML}$|⁠), a quantified variant of dynamic epistemic logic (DEL). In contrast with DEL where it is commonly known to whom agent names refer, |$\textsf {DTML}$| can represent dynamics with uncertainty about agent identity. We exemplify dynamics where such uncertainty and de re/de dicto distinctions are key to social network epistemics. Technically, we show that |$\textsf {DTML}$| semantics can represent a popular class of hybrid logic epistemic social network models. We also show that |$\textsf {DTML}$| can encode previously discussed dynamics for which finding a complete logic was left open. As complete reduction axioms systems exist for |$\textsf {DTML}$|⁠, this yields a complete system for the dynamics in question.

The literature on awareness modelling includes both syntax-free and syntax-based frameworks. Heifetz, Meier and Schipper (HMS) propose a lattice model of awareness that is syntax-free. While their lattice approach is elegant and intuitive, it does not explicitly distinguish uncertainty from unawareness. Contra this, the most prominent syntax-based solution, the Fagin–Halpern (FH) model, accounts for this distinction and offers a simple representation of awareness but lacks the intuitiveness of the lattice structure. Here, we combine these two approaches by providing a lattice of Kripke models, induced by atom subset inclusion, in which uncertainty and unawareness are separate. We show that our model is equivalent to both HMS and FH models by defining transformations between them which preserve satisfaction of formulas of a language for explicit knowledge and obtain completeness through our and HMS’ results. Lastly, we prove that the Kripke lattice model can be shown equivalent to the FH model (when awareness is propositionally determined) also with respect to the language of the Logic of General Awareness, for which the FH model was originally proposed.

In a recent paper, Christian List (2014) has argued for the compatibilism of free will and determinism. Drawing on a distinction between physical possibility (used in defining determinism) and agential possibility (used in defining free will), List constructs a formal two-level model in which the two concepts are consistent. This paper's first contribution is to show that though List's model is formally consistent, philosophically it falls short of establishing a satisfactory compatibilist position. Ensuingly, an analysis of the shortcomings of the model leads to the identification of a controversial epistemological assumption implicit in the statements of both compatibilist and incompatibilist positions. Arguing that this assumption is not currently satisfied, the paper's second contribution is to show that neither the compatibilist nor the incompatibilist position is presently well-founded.