منابع مشابه
Braid-positive Legendrian links
Any link that is the closure of a positive braid has a natural Legendrian representative. These were introduced in [15], where their Chekanov– Eliashberg contact homology was also evaluated. In this paper we rephrase and improve that computation using a matrix representation. In particular, we present a way of finding all augmentations of such Legendrians, construct an augmentation which is als...
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Let S(D) be the surface produced by applying Seifert’s algorithm to the oriented link diagram D. I prove that if D has no negative crossings then S(D) is a quasipositive Seifert surface, that is, S(D) embeds incompressibly on a fiber surface plumbed from positive Hopf annuli. This result, combined with the truth of the “local Thom Conjecture”, has various interesting consequences; for instance,...
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We analyze properties of links which have diagrams with a small number of negative crossings. We show that if a nontrivial link has a diagram with all crossings positive except possibly one, then the signature of the link is negative. If a link diagram has two negative crossings, we show that the signature of the link is nonpositive with the exception of the left-handed Hopf link (with possible...
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Detecting communities in complex networks accurately is a prime challenge, preceding further analyses of network characteristics and dynamics. Until now, community detection took into account only positively valued links, while many actual networks also feature negative links. We extend an existing Potts model to incorporate negative links as well, resulting in a method similar to the clusterin...
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Social networks and interactions in social media involve both positive and negative relationships. Signed graphs capture both types of relationships: positive edges correspond to pairs of “friends”, and negative edges to pairs of “foes”. The edge sign prediction problem, that aims to predict whether an interaction between a pair of nodes will be positive or negative, is an important graph minin...
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ژورنال
عنوان ژورنال: Algebraic & Geometric Topology
سال: 2014
ISSN: 1472-2739,1472-2747
DOI: 10.2140/agt.2014.14.2259