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We show that any separated essentially finite-type map $f$ of noetherian schemes globally factors as $f = hi$ where $i$ is an injective localization map and $h$ a separated finite-type map. In particular, via Nagata's compactification…

Algebraic Geometry · Mathematics 2008-09-09 Suresh Nayak

Tensor factorizations are computationally hard problems, and in particular, are often significantly harder than their matrix counterparts. In case of Boolean tensor factorizations -- where the input tensor and all the factors are required…

Numerical Analysis · Computer Science 2016-09-19 Saskia Metzler , Pauli Miettinen

How far can the elementary description of centralizers of parabolic subalgebras of Hecke algebras of finite real reflection groups be generalized to the complex reflection group case? In this paper we begin to answer this question by…

Representation Theory · Mathematics 2007-07-20 Andrew Francis

A graph is c-closed if every pair of vertices with at least c common neighbors is adjacent. The c-closure of a graph G is the smallest number such that G is c-closed. Fox et al. [ICALP '18] defined c-closure and investigated it in the…

Discrete Mathematics · Computer Science 2022-06-22 Tomohiro Koana , Christian Komusiewicz , Frank Sommer

In this paper we provide a method to study critical points of strongly indefinite functionals on vector bundles. We focus mainly on energy functionals coupled with a fermionic part, that is with a Dirac-type operator. We consider the cases…

Analysis of PDEs · Mathematics 2017-05-16 Ali Maalaoui

A set of points $P$ in a metric space and a constant integer $k$ are given. The $k$-center problem finds $k$ points as centers among $P$, such that the maximum distance of any point of $P$ to their closest centers $(r)$ is minimized.…

Data Structures and Algorithms · Computer Science 2019-04-25 Sepideh Aghamolaei , Mohammad Ghodsi

The $k$-Means clustering problem on $n$ points is NP-Hard for any dimension $d\ge 2$, however, for the 1D case there exists exact polynomial time algorithms. Previous literature reported an $O(kn^2)$ time dynamic programming algorithm that…

Data Structures and Algorithms · Computer Science 2018-04-26 Allan Grønlund , Kasper Green Larsen , Alexander Mathiasen , Jesper Sindahl Nielsen , Stefan Schneider , Mingzhou Song

The paper deals with various centering problems for probability measures on finite dimensional vector spaces. We show that for every such measure there exists a vector $h$ satisfying $\mu*\delta(h)=S(\mu*\delta (h))$ for each symmetry $S$…

Probability · Mathematics 2010-01-13 Andrzej Łuczak

This work extends the factorization method to the inverse scattering problem of reconstructing the shape and location of an absorbing penetrable scatterer embedded in a thin infinite elastic (Kirchhoff--Love) plate. With the assumption that…

Analysis of PDEs · Mathematics 2025-11-13 Rafael Ceja Ayala , Isaac Harris , General Ozochiawaeze

We consider the classic Facility Location, $k$-Median, and $k$-Means problems in metric spaces of doubling dimension $d$. We give nearly linear-time approximation schemes for each problem. The complexity of our algorithms is…

Data Structures and Algorithms · Computer Science 2020-05-21 Vincent Cohen-Addad , Andreas Emil Feldmann , David Saulpic

The k-means objective is arguably the most widely-used cost function for modeling clustering tasks in a metric space. In practice and historically, k-means is thought of in a continuous setting, namely where the centers can be located…

Computational Complexity · Computer Science 2020-10-08 Vincent Cohen-Addad , Karthik C. S. , Euiwoong Lee

Building on the work of the fourth author in math.AG/9904074, we prove the weak factorization conjecture for birational maps in characteristic zero: a birational map between complete nonsingular varieties over an algebraically closed field…

Algebraic Geometry · Mathematics 2007-05-23 Dan Abramovich , Kalle Karu , Kenji Matsuki , Jarosław Włodarczyk

In this paper we will give a similar factorization as in \cite{4}, \cite{5}, where the autors Svrtan and Meljanac examined certain matrix factorizations on Fock-like representation of a multiparametric quon algebra on the free associative…

Rings and Algebras · Mathematics 2015-04-13 Milena Sosic

We present two conjectures regarding the running time of computing symmetric factorizations for a Hankel matrix $\mathbf{H}$ and its inverse $\mathbf{H}^{-1}$ as $\mathbf{B}\mathbf{B}^*$ under fixed-point arithmetic. If solved, these would…

Numerical Analysis · Mathematics 2023-07-04 Mehrdad Ghadiri

$k$-Clustering in $\mathbb{R}^d$ (e.g., $k$-median and $k$-means) is a fundamental machine learning problem. While near-linear time approximation algorithms were known in the classical setting for a dataset with cardinality $n$, it remains…

Quantum Physics · Physics 2023-06-06 Yecheng Xue , Xiaoyu Chen , Tongyang Li , Shaofeng H. -C. Jiang

In the past few years powerful generalizations to the Euclidean k-means problem have been made, such as Bregman clustering [7], co-clustering (i.e., simultaneous clustering of rows and columns of an input matrix) [9,18], and tensor…

Data Structures and Algorithms · Computer Science 2009-11-09 Stefanie Jegelka , Suvrit Sra , Arindam Banerjee

We present a combinatorial model for cluster algebras of type $D_n$ in terms of centrally symmetric pseudotriangulations of a regular $2n$-gon with a small disk in the centre. This model provides convenient and uniform interpretations for…

Commutative Algebra · Mathematics 2023-11-14 Cesar Ceballos , Vincent Pilaud

Although powers of the Young-Jucys-Murphya elements X_i = (1 i) + ... +(i-1 i), i = 1, ..., n, in the symmetric group S_n acting on {1, ...,n} do not lie in the centre of the group algebra of S_n, we show that transitive powers, namely the…

Combinatorics · Mathematics 2007-05-23 I. P. Goulden , D. M. Jackson

We describe the center of the Hecke algebra of a type attached to a Bernstein block under some hypothesis. When $\bf G$ is a connected reductive group over non-archimedean local field $F$ that splits over a tamely ramified extension of $F$…

Representation Theory · Mathematics 2024-03-04 Reda Boumasmoud , Radhika Ganapathy

Given a finite metric space $(X\cup Y, \mathbf{d})$ the $k$-median problem is to find a set of $k$ centers $C\subseteq Y$ that minimizes $\sum_{p\in X} \min_{c\in C} \mathbf{d}(p,c)$. In general metrics, the best polynomial time algorithm…

Data Structures and Algorithms · Computer Science 2026-03-26 Anne Driemel , Jan Höckendorff , Ioannis Psarros , Christian Sohler , Di Yue