Revisits Van Est theory for Lie groupoids using homotopy inverses.
problem Relating Lie groupoids and their Lie algebroids cohomology.
method Using the Perturbation Lemma from homological algebra to construct homotopy inverses.
result Constructs homotopy inverses to the van Est differentiation maps at the cochain level.
Match van Stockum dust to vacuum metrics with a single parameter.
problem Matching van Stockum dust to vacuum metrics.
method 1-parametric family of non-static Papapetrou vacuum metrics, Ehlers and Kramer--Neugebauer transformations.
result Explicit examples of matching, including Bonnor metric and Lanczos--van Stockum dust metric.
The Van Est homomorphism for a Lie groupoid G⇉M, as introduced by Weinstein-Xu, is a cochain map from the complex C∞(BG) of groupoid cochains to the Chevalley-Eilenberg complex C(A) of the Lie algebroid A of G. It was generalized by Weinstein, Mehta, and Abad-Crainic to a morphism from…
New theorem shows embedding restrictions for manifold skeletons.
problem Embedding restrictions for triangulated manifolds.
method Proves van Kampen-Flores theorem for manifolds with specific Stiefel-Whitney classes.
result Triangulated manifolds with non-trivial Stiefel-Whitney classes cannot embed into R2d. Simple ML models generate art completions.
problem Creating art through machine learning.
method Single-output classification and regression models trained on various image datasets.
result Generated images complete missing parts of input images.
Enhances statistical mechanics solving using VANs with MCMC or importance sampling.
problem Sampling error in solving statistical mechanics using VANs.
method Integrates MCMC or importance sampling to correct sampling error in VANs.
result Asymptotically unbiased estimators for physical quantities are achieved.
Analyses cohomology relations for moving frames and coframes.
problem Relating Hopf cyclic cohomology of moving frames and coframes.
method Uses van Est analogy for DG Hopf algebras.
result Establishes cohomology isomorphism for DG Hopf algebras.
We answer Question 6.12 in the paper "Monoids in the mapping class group" written by Etnyre and Van Horn-Morris.
The paper derives Gauss-Bonnet theorems for deformed connections in affine and rigid motions groups.
problem Computing curvature and geodesic curvature for surfaces and curves in affine and rigid motions groups.
method Defined deformed Schouten-Van Kampen connections, computed Gaussian curvature limits, and signed geodesic curvature.
result Derived Gauss-Bonnet theorems for deformed connections in affine and rigid motions groups.
We exhibit relations between van Kampen-Flores, Conway-Gordon-Sachs and Radon theorems, by presenting direct proofs of some implications between them. The key idea is an interesting relation between the van Kampen and the Conway-Gordon-Sachs numbers for restrictions of a map of (d+2)-simplex to Rd to the $…
VB-groupoids define a special class of Lie groupoids which carry a compatible linear structure. In this paper, we show that their differentiable cohomology admits a refinement by considering the complex of cochains which are k-homogeneous on the linear fiber. Our main result is a Van Est theorem for such cochains. We a…
Graphs from van der Corput sequence embed into Chamanara surface.
problem Embedding graphs from van der Corput sequence into surfaces.
method Constructed 4-regular graphs from van der Corput sequence and Kronecker sequence, embedded into torus and Chamanara surface. result Graphs from van der Corput sequence embed into Chamanara surface with one edge removal.
We present the Variational Adaptive Newton (VAN) method which is a black-box optimization method especially suitable for explorative-learning tasks such as active learning and reinforcement learning. Similar to Bayesian methods, VAN estimates a distribution that can be used for exploration, but requires computations th…
Generalizes van Est map to sheaves of sections taking values in G-modules.
problem Classifying geometric structures involving Lie groupoids and stacks.
method Infinitesimal description of G-modules and generalized van Est map. result Definition and study of the generalized van Est map.
Study finds multiple solutions for Van der Waals-Cahn-Hilliard equation on manifolds.
problem Finding multiple solutions for a specific equation on manifolds.
method Combines Lusternik-Schnirelman and Morse theory with a photography method.
result Establishes multiplicity of solutions using topological invariants.
Generalizes van Est map to geometric stacks and homotopy theory.
problem Computing cohomology of geometric stacks and Lie algebroids.
method Generalizes van Est map to stacks and foliations, using modules instead of representations.
result Derives new cohomology results and unifies differentiable stacks, Lie algebroids, and homotopy theory.
Embeddability of simplicial complex [3]∗K linked to K's embeddability.
problem Relating embeddability of [3]∗K to K's embeddability. method Comparing embeddability conditions for K and [3]∗K. result Embeddability of [3]∗K equivalent to vanishing van Kampen obstruction for K. Maps Lie 2-groups to Weil algebras, showing cohomology isomorphisms.
problem Cohomology of strict Lie 2-groups.
method Constructs van Est map using double complex and Weil algebra.
result Induces isomorphisms in cohomology under connectedness.
A cubic identity for the Infeld-van der Waerden field is found and its application to verifying an explicit formula for the spinor components of the metric connection is demonstrated.
New method uses quantum annealing and VAN for better statistical mechanics calculations.
problem Difficulty in computing partition function in statistical mechanics.
method Combines quantum annealing samples with variational autoregressive networks.
result Enhanced accuracy in finite-size Sherrington-Kirkpatrick model.
We generalize C. Van Cott's results on the τ and s-invariants of cabled knots to apply to general satellite knots. This paper uses no Heegaard-Floer homology, relying on more geometric techniques.
Study finds multiple solutions to a complex equation with volume constraint.
problem Finding multiple solutions to a nonlinear elliptic equation with a specific potential.
method Analyzes a Van der Waals-Allen-Cahn-Hilliard equation with a linear volume constraint on a bounded Lipschitz domain.
result Estimates the number of solutions using topological and homological invariants.
This paper belongs to a series devoted to the study of the cohomology of classifying spaces. Generalizing the Weil algebra of a Lie algebra and Kalkman's BRST model, here we introduce the Weil algebra W(A) associated to any Lie algebroid A. We then show that this Weil algebra is related to the Bott-Shulman-Stasheff…
Groupoids help define Riemann sums on manifolds.
problem Defining Riemann sums on compact manifolds.
method Using groupoids and the van Est map.
result Riemann sums converge to the usual integral.
We study the Schouten-van Kampen connection associated to an almost contact or paracontact metric structure. With the help of such a connection, some classes of almost (para) contact metric manifolds are characterized. Certain curvature properties of this connection are found.
New connections defined for a specific geometric structure.
problem Characterizing manifolds with a paracontact structure.
method Introduced and studied a pair of associated Schouten-van Kampen affine connections.
result Curvature properties of the connections are obtained.
The paper calculates curvature limits and Gauss-Bonnet theorems in the Heisenberg group.
problem Computing curvature limits and Gauss-Bonnet theorems in the Heisenberg group.
method Sub-Riemannian limits of Gaussian curvature, Schouten-Van Kampen affine connections, and adapted connections.
result Gauss-Bonnet theorems associated with Schouten-Van Kampen affine connections in the Heisenberg group.
Proves integrability of strict Lie 2-algebras using cohomological methods.
problem Integrability of strict Lie 2-algebras.
method Van Est theorems relating cohomologies of Lie 2-groups and algebras.
result Proves integrability of Lie 2-algebras.
In the first section we discuss Morita invariance of differentiable/algebroid cohomology. In the second section we present an extension of the van Est isomorphism to groupoids. This immediately implies a version of Haefliger's conjecture for differentiable cohomology. As a first application we clarify the connection be…
Paper derives closed-form solutions for CEV model using semiclassical approximation.
problem Analyzing the constant elasticity variance (CEV) option pricing model.
method Utilizes semiclassical (WKB) approximation and Van Vleck-Morette determinant.
result Derives an exponential factor not previously considered in the kernel.
Researchers define and evaluate quasi-local mass near axially symmetric null infinity.
problem Defining and evaluating quasi-local mass at null infinity.
method Using Bondi-van der Burg-Metzner coordinates, the researchers evaluate the Wang-Yau quasilocal mass on surfaces of unit size at null infinity of axi-symmetric spacetimes.
result Evaluation of quasi-local mass near axially symmetric null infinity.
Paper calculates homotopy types of non-compact surfaces using groupoids.
problem Computing homotopy types of non-compact foliated surfaces.
method Application of van Kampen theorem for groupoids.
result Computation of homotopy types for specific non-compact surfaces.
There are introduced and studied a pair of associated Schouten-van Kampen affine connections adapted to the contact distribution and an almost contact B-metric structure generated by the pair of associated B-metrics and their Levi-Civita connections. By means of the constructed non-symmetric connections, the basic clas…
A map φ:K→R2 of a graph K is approximable by embeddings, if for each ε>0 there is an ε-close to φ embedding f:K→R2. Analogous notions were studied in computer science under the names of cluster planarity and weak simplicity. This short survey is intended not only for …
t-distributed Stochastic Neighborhood Embedding (t-SNE), a clustering and visualization method proposed by van der Maaten & Hinton in 2008, has rapidly become a standard tool in a number of natural sciences. Despite its overwhelming success, there is a distinct lack of mathematical foundations and the inner workings of…
Computes knot groups for torus links using Seifert-van Kampen theorem.
problem Computing knot groups for torus links.
method Groupoid version of the Seifert-van Kampen theorem.
result Economical presentations of knot groups for torus links.
Proves generic nondegeneracy for solutions under volume constraint in closed manifolds.
problem Proving nondegeneracy for solutions of the Van der Waals-Allen-Cahn-Hilliard equation.
method Adapting techniques from previous research to prove nondegeneracy.
result Generic nondegeneracy for solutions of the Van der Waals-Allen-Cahn-Hilliard equation under a volume constraint in closed manifolds.
Study hypoelliptic operators on Carnot manifolds, extending index theory results.
problem Index theory of hypoelliptic operators on Carnot manifolds.
method Operator K-theory and geometric K-homology.
result Compute Fredholm index of hypoelliptic operators on Carnot manifolds.
Geometrically solves differentiating simplicial manifolds.
problem Differentiating simplicial manifolds.
method Establishes a normal form theorem, identifies a differentiating ideal, proves quotient semi-freeness, interprets as Chevalley-Eilenberg algebra of higher Lie algebroid.
result Introduces higher van Est map and proves van Est isomorphism theorem.
Study vector bundles over Lie groupoids, controlling their deformations.
problem Understanding deformations of vector bundles over Lie groupoids.
method Attach cochain complexes to VB-groupoids to control deformations, discuss Morita invariance and van Est theorem.
result Fundamental features of VB-groupoids' deformations, including Morita invariance and van Est theorem.
New estimate reduces overfitting risk in machine learning models.
problem Error rate on test data may not reflect true population error due to adaptive data analysis practices.
method Introduces Rip van Winkle's Razor, a simple estimate of overfit to test data based on information content.
result Shows non-vacuous estimate of deviation in many modern settings.
We consider a team of reinforcement learning agents that concurrently operate in a common environment, and we develop an approach to efficient coordinated exploration that is suitable for problems of practical scale. Our approach builds on seed sampling (Dimakopoulou and Van Roy, 2018) and randomized value function lea…
Global homotopies upgrade classical map in differential geometry.
problem Upgrade classical Hochschild-Kostant-Rosenberg map to a deformation retract.
method Combining symbol calculus and coalgebraic van Est theorem.
result Develop deformation retracts in various settings.
Maps geometric deformations to algebraic classes in Lie groupoids and algebroids.
problem Deformation theory of Lie groupoids and algebroids.
method Defining a morphism between deformation complexes and Hochschild complexes, applying to adiabatic groupoids.
result Induced van Est map from geometric to algebraic deformation cohomology.
New method uses autoregressive models for dynamic planning.
problem Planning in dynamic environments with moving obstacles and goals.
method Conditional autoregressive generative models in a discrete latent space.
result Method nearly matches true environment performance for planning.
Given a front projection of a Legendrian knot K in R3 which has been cut into several pieces along vertical lines, we assign a differential graded algebra to each piece and prove a van Kampen theorem describing the Chekanov-Eliashberg invariant of K as a pushout of these algebras. We then use this the…
New findings on embedding simplicial complexes, showing instability under joins.
problem Conditions for embedding simplicial complexes into double dimension.
method Study of van Kampen obstructions and Smith classes.
result Smith index is not stable under joins, leading to new embeddability results.
We develop an algebraic framework for the description and analysis of financial behaviours, that is, behaviours that consist of transferring certain amounts of money at planned times. To a large extent, analysis of financial products amounts to analysis of such behaviours. We formalize the cumulative interest compliant…