English
Related papers

Related papers: Extractors for Images of Varieties

200 papers

We consider the following basic problem: given an $n$-variate degree-$d$ homogeneous polynomial $f$ with real coefficients, compute a unit vector $x \in \mathbb{R}^n$ that maximizes $|f(x)|$. Besides its fundamental nature, this problem…

Data Structures and Algorithms · Computer Science 2017-04-25 Vijay Bhattiprolu , Mrinalkanti Ghosh , Venkatesan Guruswami , Euiwoong Lee , Madhur Tulsiani

We investigate 2-variable expanders and 3-source extractors in prime fields. We extend previous results of J. Bourgain.

Number Theory · Mathematics 2015-06-05 Norbert Hegyvári , François Hennecart

We begin a systematic investigation of derived categories of smooth projective toric varieties defined over an arbitrary base field. We show that, in many cases, toric varieties admit full exceptional collections. Examples include all toric…

Algebraic Geometry · Mathematics 2019-08-14 Matthew R. Ballard , Alexander Duncan , Patrick K. McFaddin

We study compressed sensing when the sampling vectors are chosen from the rows of a unitary matrix. In the literature, these sampling vectors are typically chosen randomly; the use of randomness has enabled major empirical and theoretical…

Information Theory · Computer Science 2026-04-07 Yaniv Plan , Matthew S. Scott , Ozgur Yilmaz

We estimate the density and its derivatives using a local polynomial approximation to the logarithm of an unknown density $f$. The estimator is guaranteed to be nonnegative and achieves the same optimal rate of convergence in the interior…

Econometrics · Economics 2020-06-03 Joris Pinkse , Karl Schurter

In this article, recent results about point processes are used in sampling theory. Precisely, we define and study a new class of sampling designs: determinantal sampling designs. The law of such designs is known, and there exists a simple…

Methodology · Statistics 2025-08-27 Vincent Loonis , Xavier Mary

This work presents a new procedure to extract features of grey-level texture images based on the discrete Schroedinger transform. This is a non-linear transform where the image is mapped as the initial probability distribution of a wave…

Computer Vision and Pattern Recognition · Computer Science 2016-12-09 João B. Florindo , Odemir M. Bruno

One can recover sparse multivariate trigonometric polynomials from few randomly taken samples with high probability (as shown by Kunis and Rauhut). We give a deterministic sampling of multivariate trigonometric polynomials inspired by…

Numerical Analysis · Mathematics 2011-01-27 Zhiqiang Xu

In this paper we prove the discrete compactness property for a wide class of p-version finite element approximations of non-elliptic variational eigenvalue problems in two and three space dimensions. In a very general framework, we find…

Numerical Analysis · Mathematics 2025-08-01 Daniele Boffi , Martin Costabel , Monique Dauge , Leszek Demkowicz , Ralf Hiptmair

Given varieties $X, Y, W$ and dominant morphisms $\phi:X\to Y$ and $f:X\to W$ such that $f$ is constant on fibres of $\phi$ , we give sufficient conditions to guarantee that $f$ descends to a rational map or a morphism $Y\to W.$ We pay…

Algebraic Geometry · Mathematics 2025-10-15 Supravat Sarkar

Let X=spec A be a normal affine variety over an algebraically closed field k of characteristic 0 endowed with an effective action of a torus T of dimension n. Let also D be a homogeneous locally nilpotent derivation on the normal affine…

Algebraic Geometry · Mathematics 2015-03-13 Alvaro Liendo

We consider statistical methods for reduction of multivariate dimensionality that have invariance and/or commutativity properties under the affine group of transformations (origin translations plus linear combinations of coordinates along…

Methodology · Statistics 2015-04-15 Robert L. Obenchain

Let W be a projective variety of dimension n+1, L a free line bundle on W, X in $H^0(L^d)$ a hypersurface of degree d which is generic among those given by sums of monomials from $L$, and let $f : Y \to X$ be a generically finite map from a…

Algebraic Geometry · Mathematics 2007-05-23 L. Chiantini , A. F. Lopez , Z. Ran

Random samples are lossy summaries which allow queries posed over the data to be approximated by applying an appropriate estimator to the sample. The effectiveness of sampling, however, hinges on estimator selection. The choice of…

Statistics Theory · Mathematics 2014-04-10 Edith Cohen

We investigate numerical differentiation formulas on irregular centers in two or more variables that are exact for polynomials of a given order and minimize an absolute seminorm of the weight vector. Error bounds are given in terms of a…

Numerical Analysis · Mathematics 2025-08-26 Oleg Davydov , Robert Schaback

We investigate Gauss maps of (not necessarily normal) projective toric varieties over an algebraically closed field of arbitrary characteristic. The main results are as follows: (1) The structure of the Gauss map of a toric variety is…

Algebraic Geometry · Mathematics 2014-03-05 Katsuhisa Furukawa , Atsushi Ito

When implementing a propagator for a constraint, one must decide about variants: When implementing min, should one also implement max? Should one implement linear equations both with and without coefficients? Constraint variants are…

Artificial Intelligence · Computer Science 2008-06-12 Christian Schulte , Guido Tack

We present new results on the classical algorithm of variable elimination, which underlies many algorithms including for probabilistic inference. The results relate to exploiting functional dependencies, allowing one to perform inference…

Artificial Intelligence · Computer Science 2020-04-21 Adnan Darwiche

Variational autoencdoers (VAE) are a popular approach to generative modelling. However, exploiting the capabilities of VAEs in practice can be difficult. Recent work on regularised and entropic autoencoders have begun to explore the…

Machine Learning · Computer Science 2022-03-02 Gregory A. Daly , Jonathan E. Fieldsend , Gavin Tabor

Currently available methods for extracting saliency maps identify parts of the input which are the most important to a specific fixed classifier. We show that this strong dependence on a given classifier hinders their performance. To…

Machine Learning · Computer Science 2020-07-21 Konrad Zolna , Krzysztof J. Geras , Kyunghyun Cho