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🔍 anastasios sidiropoulos 📄 Preprint
Showing 37 results for "anastasios sidiropoulos" · Preprint
Physics Preprint PDF DOI

On the trivalent junction of three non-tachyonic heterotic string theories

Yuji Tachikawa · 2026

Recently, Altavista, Anastasi, Angius and Uranga discussed a method to construct junctions and bouquets of different perturbative string theories. Following this analysis, we here argue that three non…

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AI & Data Science Preprint PDF DOI

Piecing Together Cross-Document Coreference Resolution Datasets: Systematic Dataset Analysis and Unification

Anastasia Zhukova, Terry Ruas, Jan Philip Wahle, Bela Gipp · 2026

Research in CDCR remains fragmented due to heterogeneous dataset formats, varying annotation standards, and the predominance of the CDCR definition as the event coreference resolution (ECR). To addres…

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Computer Science Preprint PDF DOI

Node-Weighted Multicut in Planar Digraphs

Chandra Chekuri, Rhea Jain · 2026

Kawarabayashi and Sidiropoulos [KS22] obtained an $O(\log^2 n)$-approximation algorithm for Multicut in planar digraphs via a natural LP relaxation, which also establishes a corresponding upper bound …

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AI & Data Science Preprint PDF DOI

Tensor time series change-point detection in cryptocurrency network data

Andreas Anastasiou, Ivor Cribben · 2025

Financial fraud has been growing exponentially in recent years. The rise of cryptocurrencies as an investment asset has simultaneously seen a parallel growth in cryptocurrency scams. To detect possibl…

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Physics Preprint PDF DOI

Inferring viscoplastic models from velocity fields: a physics-informed neural network approach

Martin Lardy, Sham Tlili, Simon Gsell · 2025

Fluid-like materials are ubiquitous, spanning from living biological tissues to geological formations, and across scales ranging from micrometers to kilometers. Inferring their rheological properties …

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Computer Science Preprint PDF DOI

When Distances Lie: Euclidean Embeddings in the Presence of Outliers and Distance Violations

Matthias Bentert, Fedor V. Fomin, Petr A. Golovach, M. S. Ramanujan, Saket Saurabh · 2025

Distance geometry explores the properties of distance spaces that can be exactly represented as the pairwise Euclidean distances between points in $\mathbb{R}^d$ ($d \geq 1$), or equivalently, distanc…

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Mathematics Preprint PDF DOI

Electric group for knots and links

Philipp Korablev · 2024

In 2014 Andrey Perfiliev introduced the so-called electric invariant for non-oriented knots. This invariant was motivated by using Kirchhoff's laws for the dual graph of the knot diagram. Later, in 20…

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Computer Science Preprint PDF DOI

Streaming Euclidean Max-Cut: Dimension vs Data Reduction

Xiaoyu Chen, Shaofeng H.-C. Jiang, Robert Krauthgamer · 2022

Max-Cut is a fundamental problem that has been studied extensively in various settings. We design an algorithm for Euclidean Max-Cut, where the input is a set of points in $\mathbb{R}^d$, in the model…

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Physics Preprint PDF DOI

BRST Symmetry and the Convolutional Double Copy

Mahdi Godazgar, C.N. Pope, A. Saha, Haoyu Zhang · 2022

Motivated by the results of Anastasiou et al., we consider the convolutional double copy for BRST and anti-BRST covariant formulations of gravitational and gauge theories in more detail. We give a gen…

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Computer Science Preprint PDF DOI

Tight Lower Bounds for Approximate & Exact $k$-Center in $\mathbb{R}^d$

Rajesh Chitnis, Nitin Saurabh · 2022

In the discrete $k$-center problem, we are given a metric space $(P,\texttt{dist})$ where $|P|=n$ and the goal is to select a set $C\subseteq P$ of $k$ centers which minimizes the maximum distance of …

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Computer Science Preprint PDF DOI

Lossy Planarization: A Constant-Factor Approximate Kernelization for Planar Vertex Deletion

Bart M. P. Jansen, Micha{l} W{l}odarczyk · 2022

In the F-minor-free deletion problem we want to find a minimum vertex set in a given graph that intersects all minor models of graphs from the family F. The Vertex planarization problem is a special c…

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Mathematics Preprint PDF DOI

Some Fuzzy Korovkin type Approximation Theorems via Power Series Summability Method

Behar Baxhaku, Purshottam Narain Agrawal, Rahul Shukla · 2022

This article provides a power series summability based Korovkin type approximation theorem for any fuzzy sequence of positive linear operators. Using the notion of fuzzy modulus of smoothness, we also…

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Computer Science Preprint PDF DOI

A face cover perspective to $\ell_1$ embeddings of planar graphs

Arnold Filtser · 2019

It was conjectured by Gupta et al. [Combinatorica04] that every planar graph can be embedded into $\ell_1$ with constant distortion. However, given an $n$-vertex weighted planar graph, the best upper …

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Computer Science Preprint PDF DOI

Flow-Cut Gaps and Face Covers in Planar Graphs

Robert Krauthgamer, James R. Lee, Havana Rika · 2018

The relationship between the sparsest cut and the maximum concurrent multi-flow in graphs has been studied extensively. For general graphs with $k$ terminal pairs, the flow-cut gap is $O(\log k)$, and…

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Computer Science Preprint PDF DOI

Light Spanners for High Dimensional Norms via Stochastic Decompositions

Arnold Filtser, Ofer Neiman · 2018

Spanners for low dimensional spaces (e.g. Euclidean space of constant dimension, or doubling metrics) are well understood. This lies in contrast to the situation in high dimensional spaces, where exce…

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Computer Science Preprint PDF DOI

Fractal dimension and lower bounds for geometric problems

Anastasios Sidiropoulos, Kritika Singhal, Vijay Sridhar · 2017

We study the complexity of geometric problems on spaces of low fractal dimension. It was recently shown by [Sidiropoulos & Sridhar, SoCG 2017] that several problems admit improved solutions when the i…

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Computer Science Preprint PDF DOI

On the complexity of optimal homotopies

Erin Wolf Chambers, Arnaud de Mesmay, Tim Ophelders · 2017

In this article, we provide new structural results and algorithms for the Homotopy Height problem. In broad terms, this problem quantifies how much a curve on a surface needs to be stretched to sweep …

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Computer Science Preprint PDF DOI

Polylogarithmic approximation for minimum planarization (almost)

Ken-ichi Kawarabayashi, Anastasios Sidiropoulos · 2017

In the minimum planarization problem, given some $n$-vertex graph, the goal is to find a set of vertices of minimum cardinality whose removal leaves a planar graph. This is a fundamental problem in to…

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Computer Science Preprint PDF DOI

Metric Embedding via Shortest Path Decompositions

Ittai Abraham, Arnold Filtser, Anupam Gupta, Ofer Neiman · 2017

We study the problem of embedding shortest-path metrics of weighted graphs into $\ell_p$ spaces. We introduce a new embedding technique based on low-depth decompositions of a graph via shortest paths.…

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Mathematics Preprint PDF DOI

A geometric method for eigenvalue problems with low rank perturbations

Thomas J. Anastasio, Andrea K. Barreiro, Jared C Bronski · 2017

We consider the problem of finding the spectrum of an operator taking the form of a low-rank (rank one or two) non-normal perturbation of a well-understood operator, motivated by a number of problems …

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