111,996 research outputs found
Spectral triples from stationary Bratteli diagrams
We construct spectral triples for path spaces of stationary Bratteli diagrams
and study their associated mathematical objects, in particular their zeta
function, their heat kernel expansion and their Dirichlet forms. One of the
main difficulties to properly define a Dirichlet form concerns its domain. We
address this question in particular in the context of Pisot substitution tiling
spaces for which we find two types of Dirichlet forms: one of transversal type,
and one of longitudinal type. Here the eigenfunctions under the translation
action can serve as a good core for a non-trivial Dirichlet form. We find that
the infinitesimal generators can be interpreted as elliptic differential
operators on the maximal equicontinuous factor of the tiling dynamical system.Comment: Version 2, 49 page
Many-Body Expanded Full Configuration Interaction. I. Weakly Correlated Regime
Over the course of the past few decades, the field of computational chemistry
has managed to manifest itself as a key complement to more traditional
lab-oriented chemistry. This is particularly true in the wake of the recent
renaissance of full configuration interaction (FCI)-level methodologies, albeit
only if these can prove themselves sufficiently robust and versatile to be
routinely applied to a variety of chemical problems of interest. In the present
series of works, performance and feature enhancements of one such avenue
towards FCI-level results for medium to large one-electron basis sets, the
recently introduced many-body expanded full configuration interaction (MBE-FCI)
formalism [J. Phys. Chem. Lett., 8, 4633 (2017)], will be presented.
Specifically, in this opening part of the series, the capabilities of the
MBE-FCI method in producing near-exact ground state energies for weakly
correlated molecules of any spin multiplicity will be demonstrated.Comment: 38 pages, 7 tables, 3 figures, 1 SI attached as an ancillary fil
Context-aware Path Ranking for Knowledge Base Completion
Knowledge base (KB) completion aims to infer missing facts from existing ones
in a KB. Among various approaches, path ranking (PR) algorithms have received
increasing attention in recent years. PR algorithms enumerate paths between
entity pairs in a KB and use those paths as features to train a model for
missing fact prediction. Due to their good performances and high model
interpretability, several methods have been proposed. However, most existing
methods suffer from scalability (high RAM consumption) and feature explosion
(trains on an exponentially large number of features) problems. This paper
proposes a Context-aware Path Ranking (C-PR) algorithm to solve these problems
by introducing a selective path exploration strategy. C-PR learns global
semantics of entities in the KB using word embedding and leverages the
knowledge of entity semantics to enumerate contextually relevant paths using
bidirectional random walk. Experimental results on three large KBs show that
the path features (fewer in number) discovered by C-PR not only improve
predictive performance but also are more interpretable than existing baselines
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