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      Boyer-Lindquist space-times and beyond: Meta-material analogues

      February 27, 2018

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      Physics
      General Relativity and Quantum Cosmology
      Analogue space-times (and in particular metamaterial analogue space-times) have a long varied and complex history. Much of the previous related work has focused on spherically symmetric models; however, axial symmetry is much more relevant ...

      Approximation Algorithms for D-optimal Design

      February 22, 2018

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      Statistics
      Computer Science
      Machine Learning
      Data Structures and Algorithms
      Machine Learning
      Data Structures and Algorithms
      Experimental design is a classical statistics problem and its aim is to estimate an unknown mmm-dimensional vector β\betaβ from linear measurements where a Gaussian noise is introduced in each measurement. For the combinatorial experimental...

      Higher Hochschild homology and exponential functors

      February 21, 2018

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      Mathematics
      Algebraic Topology
      Algebraic Topology
      We study higher Hochschild homology evaluated on wedges of circles, viewed as a functor on the category of free groups. The main results use coefficients arising from square-zero extensions; this is motivated by work of Turchin and Willwach...

      A Note on Coherent States for Virasoro Orbits

      February 21, 2018

      Physics
      High Energy Physics - Theory
      There are two sets of orbits of the Virasoro group which admit a K\"ahler structure. We consider the construction of coherent states for the orbit diff S1^\widehat{{\rm diff}\,S^1}diffS1/SL(2,R)SL(2, {\mathbb R})SL(2,R) which furnishes unitary representations of t...

      The Malicious Use of Artificial Intelligence: Forecasting, Prevention, and Mitigation

      February 20, 2018

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      Computer Science
      Artificial Intelligence
      Cryptography and Security
      Computers and Society
      Artificial Intelligence
      Cryptography and Security
      Computers and Society
      This report surveys the landscape of potential security threats from malicious uses of AI, and proposes ways to better forecast, prevent, and mitigate these threats. After analyzing the ways in which AI may influence the threat landscape in...

      Causal Perturbative QFT and Space-time Geometry

      February 19, 2018

      Physics
      Mathematics
      Mathematical Physics
      Mathematical Physics
      This work is devoted to the causal perturbative Quantum Field Theory (QFT) due to Bogoliubov, including QED and other realistic QFT. The white noise analysis and the Hida operators as the creation and annihilation operators for free fields ...

      Dynamics of strongly interacting unstable two-solitons for generalized Korteweg-de Vries equations

      February 17, 2018

      Mathematics
      Analysis of PDEs
      We consider the generalized Korteweg-de Vries equation ∂tu=−∂x(∂x2u+f(u))\partial_t u = -\partial_x(\partial_x^2 u + f(u))∂t​u=−∂x​(∂x2​u+f(u)), where f(u)f(u)f(u) is an odd function of class C3C^3C3. Under some assumptions on fff, this equation admits \emph{solitary waves}, that is s...

      Optimizing generalized kernels of polygons

      February 16, 2018

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      Computer Science
      Computational Geometry
      Computational Geometry
      Let O\mathcal{O}O be a set of kkk orientations in the plane, and let PPP be a simple polygon in the plane. Given two points p,qp,qp,q inside PPP, we say that ppp O\mathcal{O}O-\emph{sees} qqq if there is an O\mathcal{O}O-\emph{staircase} contai...

      Minimal Algorithmic Information Loss Methods for Dimension Reduction, Feature Selection and Network Sparsification

      February 16, 2018

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      Computer Science
      Mathematics
      Physics
      Data Structures and Algorithms
      Information Theory
      Information Theory
      Physics and Society
      We present a novel, domain-agnostic, model-independent, unsupervised, and universally applicable approach for data summarization. Specifically, we focus on addressing the challenge of reducing certain dimensionality aspects, such as the num...

      Chromatic symmetric functions via the group algebra of SnS_nSn​

      February 15, 2018

      Mathematics
      Combinatorics
      Representation Theory
      We prove some Schur positivity results for the chromatic symmetric function XGX_GXG​ of a (hyper)graph GGG, using connections to the group algebra of the symmetric group. The first such connection works for (hyper)forests FFF: we describe the ...
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