The finitary coding of two Bernoulli schemes with unequal entropies has finite expectation

AbstractIt is well known that for any two Bernoulli schemes with a finite number of states and unequal entropies, there exists a finitary homomorphism from the scheme with the larger entropy to the one with smaller entropy. We prove that the average number of coordinates in the larger entropy scheme needed to determine one coordinate in the image point is finite

Stalling the State: How Digital Platforms Contribute to and Profit From Delays in the Enforcement and Adoption of Regulations

While it is often claimed that the pace of digital transformation is such that its own, often glacial changes do not allow the state to catch up, we argue that technological companies, with the help of some state actors, have been slowing the state down. To capture this phenomenon, we introduce the notion of stalling strategies. We argue that stalling strategies have allowed digital platforms to create time that they have spent generating revenue and accumulating platform power, which later protected them from state actions. Drawing on a case study of Uber in Poland and a number of shadow cases, we distinguish five stalling strategies: reinventing classifications, dragging out court proceedings, stealing the time of street-level bureaucrats, delaying new regulations, and taking time to (not) comply. By analyzing stalling strategies, this article contributes to discussions about the politics of platform capitalism, the temporality of digitalization, and institutional drift.Introduction Theory: Primitive Accumulation of Platform Power and Stalling Strategies Case Selection and Data Stalling Strategies Beyond the Particular Case: Stalling to Accumulate Platform Power, Stalling to Protect It Conclusion: Platform Power as a Fait Accompli Acknowledgements Notes Reference

Destruction of chain-superconductivity in YBa_2Cu_4O_8 in a weak magnetic field

We report measurements of the temperature dependent components of the magnetic penetration depth {\lambda}(T) in single crystal samples of YBa_2Cu_4O_8 using a radio frequency tunnel diode oscillator technique. We observe a downturn in {\lambda}(T) at low temperatures for currents flowing along the b and c axes but not along the a axis. The downturn in {\lambda}_b is suppressed by a small dc field of ~0.25 T. This and the zero field anisotropy of {\lambda}(T) likely result from proximity induced superconducting on the CuO chains, however we also discuss the possibility that a significant part of the anisotropy might originate from the CuO2 planes.Comment: 5 page

A Proposal for Semantic Map Representation and Evaluation

Semantic mapping is the incremental process of “mapping” relevant information of the world (i.e., spatial information, temporal events, agents and actions) to a formal description supported by a reasoning engine. Current research focuses on learning the semantic of environments based on their spatial location, geometry and appearance. Many methods to tackle this problem have been proposed, but the lack of a uniform representation, as well as standard benchmarking suites, prevents their direct comparison. In this paper, we propose a standardization in the representation of semantic maps, by defining an easily extensible formalism to be used on top of metric maps of the environments. Based on this, we describe the procedure to build a dataset (based on real sensor data) for benchmarking semantic mapping techniques, also hypothesizing some possible evaluation metrics. Nevertheless, by providing a tool for the construction of a semantic map ground truth, we aim at the contribution of the scientific community in acquiring data for populating the dataset

A bound on the free energy of tensionless membranes

Using the proof of Willmore's conjecure by Marques and Neves, we conjecture that the free energy of tensionless fluid membranes of arbitrary genus has an upper bound. This implies that the average genus of such a membrane, in equilibrium, is finite, regardless of external constraints.Comment: 4 pages, 1 figur

Evidence for nodal superconductivity in LaFePO

In several iron-arsenide superconductors there is strong evidence for a fully gapped superconducting state consistent with either a conventional s-wave symmetry or an unusual $s_\pm$ state where there the gap changes sign between the electron and hole Fermi surface sheets. Here we report measurements of the penetration depth $\lambda(T)$ in very clean samples of the related iron-phosphide superconductor, LaFePO, at temperatures down to $\sim$ 100 mK. We find that $\lambda(T)$ varies almost perfectly linearly with $T$ strongly suggesting the presence of gap nodes in this compound. Taken together with other data, this suggests the gap function may not be generic to all pnictide superconductors