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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,742 papers · 148 categories

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8162432 · Jul 202519922001200920172026
48 results for étale cohomology

Anabelian geometry reformulated using Hodge theory for hyperbolic curves.

problem Determining varieties over number fields using their étale fundamental groups.
method Formulating a Hodge-theoretic version of anabelian conjecture, replacing Galois action with Cimes\mathbb{C}^ imes-action.
result Proved a Hodge-theoretic analog of Mochizuki's theorem for smooth projective hyperbolic curves over C\mathbb{C}.

Tangle machines are a topologically inspired diagrammatic formalism to describe information flow in networks. This paper begins with an expository account of tangle machines motivated by the problem of describing `covariance intersection' fusion of Gaussian estimators in networks. It then gives two examples in which ta…

2015-11-16abs ↗pdf ↗

An orbifold is a Morita equivalence class of a proper {\' e}tale Lie groupoid. A unitary equivalence class of spectral triples over the algebra of smooth invariant functions are associated with any compact spin orbifold. In the case of an effective spin orbifold we construct a collection of spectral triples over the sm…

2014-05-28abs ↗pdf ↗

We consider the partial observability model for multi-armed bandits, introduced by Mannor and Shamir. Our main result is a characterization of regret in the directed observability model in terms of the dominating and independence numbers of the observability graph. We also show that in the undirected case, the learner …

2013-07-17abs ↗pdf ↗

This paper investigates arbitrage chains involving four currencies and four foreign exchange trader-arbitrageurs. In contrast with the three-currency case, we find that arbitrage operations when four currencies are present may appear periodic in nature, and not involve smooth convergence to a "balanced" ensemble of exc…

2011-12-26abs ↗pdf ↗

Feature selection from wide datasets leads to misleading results.

problem Feature selection in wide datasets with few samples can lead to misleading results.
method Derived sample size requirement for declaring features different, used real datasets to illustrate issues.
result Feature selection from very wide datasets may lead to misleading results.

The paper explores tail diversification in financial markets using entropy and mutual information.

problem Tail diversification in financial time series.
method Statistical independence through differential entropy and mutual information, using moments as contrast functions.
result Tail covariance matrix is a key driver of tail diversification.

Framework combines adversarial training and provable robustness for neural networks.

problem Training certifiably robust neural networks with provable robustness guarantees.
method Formulates joint optimization problem with adversarial and provable robustness objectives; develops gradient-descent technique.
result Consistently matches or outperforms prior approaches for provable l infinity robustness on MNIST and CIFAR-10.

Two case studies reveal hidden biases and confounders in machine learning models of biomedical data.

problem Hidden biases and confounders in machine learning models of biomedical data.
method Two case studies examining biases and confounders in machine learning models of biomedical data.
result Prediction models performed well but hidden biases and confounders were revealed.

Lecture notes on linear neural networks for deep learning optimization and generalization.

problem Understanding optimization and generalization in deep learning models.
method Mathematical tools and dynamical systems theory.
result Potential of mathematical tools to enhance understanding of deep learning.

HIVE-COTE v1.0 improves time series classification with enhanced usability.

problem Improving time series classification accuracy and usability.
method Presented a walkthrough guide and extensive experimental evaluation of HIVE-COTE v1.0.
result HIVE-COTE v1.0 outperforms three recently proposed algorithms in predictive performance and resource usage.

In healthcare, patient risk stratification models are often learned using time-series data extracted from electronic health records. When extracting data for a clinical prediction task, several formulations exist, depending on how one chooses the time of prediction and the prediction horizon. In this paper, we show how…

2018-11-29abs ↗pdf ↗

Integration of the form af(x)w(x)dx\int_a^\infty {f(x)w(x)dx} , where w(x)w(x) is either sin(ωx)\sin (ω{\kern 1pt} x) or cos(ωx)\cos (ω{\kern 1pt} x), is widely encountered in many engineering and scientific applications, such as those involving Fourier or Laplace transforms. Often such integrals are approximated by a numerical integration…

2010-05-11abs ↗pdf ↗

For any Lie groupoid we construct an analytic index morphism taking values in a modified KtheoryK-theory group which involves the convolution algebra of compactly supported smooth functions over the groupoid. The construction is performed by using the deformation algebra of smooth functions over the tangent groupoid constru…

2008-03-13abs ↗pdf ↗

In this short note we define a new cohomology for a Lie algebroid A\mathcal{A}, that we call the \emph{twisted cohomology} of A\mathcal{A} by an odd cocycle θθ in the Lie algebroid cohomology of A\mathcal{A}. We proof that this cohomology only depends on the Lie algebroid cohomology class [θ][θ] of the odd cocycle $…

2017-06-13abs ↗pdf ↗

The article examines twisted cohomologies on algebraic and analytic varieties.

problem Understanding and comparing twisted cohomologies on algebraic and analytic varieties.
method Comparison and definition of twisting parameters in both categories, algebraic and analytic.
result Reviewed isomorphisms of twisted cohomologies for cohomologous twisting parameters.

GANs can bias synthetic data, affecting minority and female faces.

problem GANs can amplify biases in synthetic data augmentation.
method Examine GANs on face-shots with gender and skin tone biases.
result GANs generate biased synthetic data, skewing minority modes and features.

We view Dolbeault-Morse-Novikov cohomology H^{p,q}_η(X) as the cohomology of the sheaf Ω_{X,η}^p of η-holomorphic p-forms and give several bimeromorphic invariants. Analogue to Dolbeault cohomology, we establish the Leray-Hirsch theorem and the blow-up formula for Dolbeault-Morse-Novikov cohomology. At last, we conside…

2018-08-03abs ↗pdf ↗

New cohomology theories for heaps and ternary operations linked to group cohomology.

problem Defining and studying cohomology theories for heaps and ternary operations.
method Introduced para-associative and heap cohomology theories, and ternary self-distributive cohomology with abelian heap coefficients.
result Heap cohomology is related to group cohomology via a long exact sequence, and injects into ternary self-distributive cohomology.

Study characterizes cohomology of Vaisman manifolds, linking Bott-Chern and Dolbeault numbers.

problem Characterize Bott-Chern cohomology of Vaisman manifolds.
method Explicit description via basic cohomology, infer relationships between cohomology groups, show invariants are unbounded, cohomological characterization of formality.
result Bott-Chern and Dolbeault numbers determine each other for Vaisman manifolds, and cohomological invariants are unbounded.

In this paper we define a new cohomology of a smooth manifold called Lichnerowicz type cohomology attached to a function. Firstly, we study some basic properties of this cohomology as: a de Rham type isomorphism, dependence on the function, singular forms, relative cohomology, Mayer-Vietoris sequence, homotopy invarian…

2012-05-04abs ↗pdf ↗

Researchers calculate cohomological dimensions of manifold configuration spaces, proving arithmeticity and providing bounds.

problem Calculating the cohomological dimensions of configuration spaces of manifolds.
method Defined a reduced Chevalley Eilenberg complex and provided precise formulas and bounds.
result Arithmeticity of cohomological dimensions in configuration spaces of manifolds with non-trivial co-dimension one cohomology groups.

Deligne cohomology can be viewed as a differential refinement of integral cohomology, hence captures both topological and geometric information. On the other hand, it can be viewed as the simplest nontrivial version of a differential cohomology theory. While more involved differential cohomology theories have been expl…

2017-06-08abs ↗pdf ↗

Investigates Künneth formula for foliated de Rham cohomology, overcoming non-Hausdorff issues.

problem Computing cohomology for foliated manifolds, especially when non-Hausdorff.
method Develops a Künneth formula for specific cases of Hausdorff foliated cohomology and finite-dimensional cohomology.
result Valid Künneth formula for certain foliated cohomology spaces, with counterexamples for others.

We give a definition of differentiable cohomology of a Lie group G (possibly infinite-dimensional) with coefficients in any abelian Lie group. This differentiable cohomology maps both to the cohomology of the group made discrete and to Lie algebra cohomology. We show that the secondary characteristic classes of Beilins…

2000-11-11abs ↗pdf ↗