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arXiv research

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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16334965 · May 202619922001200920172026
48 results for Diederich-Fornæss index

A smooth curve $γ: [0,1] \to \Ss^2$ is locally convex if its geodesic curvature is positive at every point. J. A. Little showed that the space of all locally convex curves γγ with γ(0)=γ(1)=e1γ(0) = γ(1) = e_1 and γ(0)=γ(1)=e2γ'(0) = γ'(1) = e_2 has three connected components L1,cL_{-1,c}, L+1L_{+1}, L1,nL_{-1,n}. The space $\cL_{-1,c}$ is kn…

2012-07-17abs ↗pdf ↗

The state space (SS) representation of Gaussian processes (GP) has recently gained a lot of interest. The main reason is that it allows to compute GPs based inferences in O(n), where nn is the number of observations. This implementation makes GPs suitable for Big Data. For this reason, it is important to provide a SS …

2016-01-07abs ↗pdf ↗

SS-GEN simulates rare events in heavy and light-tailed data.

problem Estimating probabilities of extreme events in multivariate data.
method Self-Similar Generative Estimation (SS-GEN) decomposes tail distribution into radial and angular components.
result SS-GEN generates representative extreme scenarios and estimates rare-event probabilities beyond observed data.

In this note we revisit the notion of conformal barycenter of a measure on $\SS^n$ as defined by Douady and Earle in Acta Math. Vol 157, 1986. The aim is to extend rational maps from the Riemann sphere $\Cbar\isom\SS^2$ to the (hyperbolic) three ball $\BB^3$ and thus to $\SS^3$ by reflection. The construction which was…

2011-02-07abs ↗pdf ↗

This paper introduces SS-MAMP to address convergence issues in AMP algorithms.

problem Convergence issues in AMP algorithms for signal reconstruction.
method Proposes SS-MAMP algorithm framework for right-unitarily invariant sensing matrices and Lipschitz-continuous local processors.
result Covariance matrices of SS-MAMP are L-banded and convergent, ensuring optimal convergence.

New method for estimating mean in SS inference with selection bias and decaying overlap.

problem Estimating mean in SS inference with selection bias and decaying overlap.
method Double Robust Semi-Supervised (DRSS) mean estimator.
result Consistent estimation of mean with correct specification of outcome or propensity score model.

Conjectures on universal structures in algebraic geometry enumerative invariants.

problem Understanding virtual classes in moduli spaces of stable objects.
method Defining virtual classes in homology over Q and proving a universal wall-crossing formula.
result Proving conjectures for quiver representations using Behrend-Fantechi virtual classes.

FLAME improves privacy in federated learning without trusted parties.

problem Ensuring privacy in federated learning without trusted parties.
method FLAME uses the shuffle model of differential privacy to achieve better accuracy and privacy.
result FLAME protocols improve testing accuracy by 60.7% compared to local model FL.

Paper proposes an efficient bandit-based algorithm for hyperparameter optimization.

problem Efficiently evaluating hyperparameters in deep learning models with large search spaces.
method Sub-Sampling (SS) algorithm combined with Bayesian Optimization (BOSS).
result Theoretical proof of optimality and empirical validation of superior performance.

We consider contracting and expanding curvature flows in $\Ss$. When the flow hypersurfaces are strictly convex we establish a relation between the contracting hypersurfaces and the expanding hypersurfaces which is given by the Gauß map. The contracting hypersurfaces shrink to a point x0x_0 while the expanding hypersur…

2013-08-07abs ↗pdf ↗

Develops robust and efficient SS estimators for treatment effects.

problem Estimating treatment effects in semi-supervised settings with limited labeled data.
method A family of SS estimators using labeled and unlabeled data, ensuring robustness and efficiency.
result Root-n consistency and asymptotic normality of SS estimators under correct specification of propensity score and nuisance functions.

A fast, approximate method for variable selection in GLMs tackles correlated data.

problem Variable selection in generalized linear models with correlated data.
method Replica method of statistical mechanics and vector approximate message passing.
result The proposed algorithm provides fast convergence and high approximation accuracy.

We construct a compactification MμssM^{μss} of the Uhlenbeck-Donaldson type for the moduli space of slope stable framed bundles. This is a kind of a moduli space of slope semistable framed sheaves. We show that there exists a projective morphism γ ⁣:MssMμssγ\colon M^{ss} \to M^{μss}, where MssM^{ss} is the moduli space of S-equiva…

2010-09-04abs ↗pdf ↗

KalmanNet uses neural networks to improve state estimation in systems with unknown dynamics.

problem State estimation of systems with non-linear dynamics and partial information.
method KalmanNet integrates a recurrent neural network with the Kalman filter to handle non-linearities and model mismatches.
result KalmanNet outperforms classic filtering methods in systems with both mismatched and accurate domain knowledge.

We propose a new random pruning method (called "submodular sparsification (SS)") to reduce the cost of submodular maximization. The pruning is applied via a "submodularity graph" over the nn ground elements, where each directed edge is associated with a pairwise dependency defined by the submodular function. In each s…

2016-06-01abs ↗pdf ↗

A new framework using kernel packets overcomes limitations of state space models for multi-dimensional data.

problem Computational limitations of Gaussian process regression in large-scale applications.
method Kernel packet approach, identifying KPs via forward and backward state space representations.
result Exact, memory-efficient inference with linear-time training and logarithmic/predictive time.

New classification of Kähler-Ricci solitons linked to isoparametric functions and contact geometry.

problem Classifying Kähler-Ricci solitons with specific functional relationships.
method Analyzing functionally dependent potential and scalar curvature, discovering connections to isoparametric functions and contact geometry.
result Complete classification of Kähler-Ricci solitons with functionally dependent potential and scalar curvature.

We prove that any flat family (Fu)uU(\mathcal{ F}_u)_{u\in U} of rank 2 torsion-free sheaves on a Gauduchon surface defines a continuous map on the semi-stable locus Uss:={uU  Fu is slope semi-stable}U^{\mathrm {ss}}:=\{u\in U \ |\ \mathcal{ F}_u\hbox{ is slope semi-stable}\} with values in the Donaldson-Uhlenbeck compactification of the corresponding in…

2016-12-30abs ↗pdf ↗

Let ΓΓ be a finite d-valent graph and G an n-dimensional torus. An ``action'' of G on ΓΓ is defined by a map, αα, which assigns to each oriented edge e of ΓΓ a one-dimensional representation of G (or, alternatively, a weight, αeα_e, in the weight lattice of G). For the assignment, eαee \to α_e, to be a schematic des…

2000-07-26abs ↗pdf ↗

Regression problems that have closed-form solutions are well understood and can be easily implemented when the dataset is small enough to be all loaded into the RAM. Challenges arise when data is too big to be stored in RAM to compute the closed form solutions. Many techniques were proposed to overcome or alleviate the…

2019-03-03abs ↗pdf ↗

Let MM be either the 2-sphere $\SS^2 \subset\RR^3$ or the hyperbolic plane $\HH^2 \subset \RR^3$. If Δ(abc)Δ(abc) is a geodesic triangle on MM with corners at a,b,cMa,b,c\in M, we denote by α,β,γMα, β, γ\in M the midpoints of their sides. If ΩΩ denotes the oriented area of this triangle on MM, it satisfies the relations: $$ \s…

2013-07-09abs ↗pdf ↗

Paper tackles causal inference with partially labeled data, introducing robust methods.

problem Challenges in causal inference due to partially labeled datasets and potential bias.
method Decaying missing-at-random framework and BRSS estimator for doubly robust causal inference.
result Established asymptotic normality of BRSS estimator under decaying labeling propensity scores.

Spike-and-Slab Deep Learning (SS-DL) is a fully Bayesian alternative to Dropout for improving generalizability of deep ReLU networks. This new type of regularization enables provable recovery of smooth input-output maps with unknown levels of smoothness. Indeed, we show that the posterior distribution concentrates at t…

2018-03-24abs ↗pdf ↗

DRSS method identifies unnecessary samples and features in DR covariate shift.

problem Identifying unnecessary samples and features in DR covariate shift.
method Combines DR learning and safe screening techniques.
result DRSS method provides reliable identification of unnecessary samples and features under specified distribution uncertainty.

Develops a new tensor PCA method for analyzing multiple network data.

problem Analyzing multiple large networks for dimensionality reduction.
method Semi-Symmetric Tensor PCA (SS-TPCA) for principal components analysis.
result SS-TPCA achieves the same estimation accuracy as classical matrix PCA, with error proportional to the square root of the number of vertices.

Third-order PDEs describe spherical and pseudospherical surfaces.

problem Equations for spherical and pseudospherical surfaces.
method Classification of third-order PDEs using compatibility conditions and linear problems.
result Explicit classification of equations describing spherical and pseudospherical surfaces.

We consider the problem of learning a sparse rule model, a prediction model in the form of a sparse linear combination of rules, where a rule is an indicator function defined over a hyper-rectangle in the input space. Since the number of all possible such rules is extremely large, it has been computationally intractabl…

2018-10-03abs ↗pdf ↗

The paper classifies equations describing spherical or pseudospherical surfaces.

problem Equations describing spherical or pseudospherical surfaces.
method Classification based on compatibility condition of linear problems.
result A complete and explicit classification of equations of the form ztt=A(z,zx,zt)zxx+B(z,zx,zt)zxt+C(z,zx,zt)z_{tt} = A(z, z_x , z_t) z_{xx} + B(z, z_x , z_t ) z_{xt} + C(z, z_x , z_t).

Deep Partition Aggregation defends against poisoning attacks with provable certificates.

problem Adversarial poisoning attacks corrupt classifier test-time behavior.
method Deep Partition Aggregation (DPA) is an ensemble method using hash partitions and base models trained on these partitions.
result DPA can certify >= 50% of test images against over 500 poison image insertions on MNIST, and nine insertions on CIFAR-10.