On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs

We consider k-regular graphs with loops, and study the Lovász ϑ-numbers and Schrijver ϑ′-numbers of the graphs that result when the loop edges are removed. We show that the ϑ-number dominates a recent eigenvalue upper bound on the stability number due to Godsil and Newman [C.D. Godsil and M.W. Newma...

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Main Authors: Sotirov, R., Klerk, Etienne de., Newman, M. W., Pasechnik, Dmitrii V.
Other Authors: School of Physical and Mathematical Sciences
Format: Journal Article
Language:English
Published: 2012
Subjects:
Online Access:https://hdl.handle.net/10356/94538
http://hdl.handle.net/10220/7516
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author Sotirov, R.
Klerk, Etienne de.
Newman, M. W.
Pasechnik, Dmitrii V.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Sotirov, R.
Klerk, Etienne de.
Newman, M. W.
Pasechnik, Dmitrii V.
author_sort Sotirov, R.
collection NTU
description We consider k-regular graphs with loops, and study the Lovász ϑ-numbers and Schrijver ϑ′-numbers of the graphs that result when the loop edges are removed. We show that the ϑ-number dominates a recent eigenvalue upper bound on the stability number due to Godsil and Newman [C.D. Godsil and M.W. Newman. Eigenvalue bounds for independent sets, J. Combin. Theory B 98 (4) (2008) 721–734]. As an application we compute the ϑ and ϑ′ numbers of certain instances of Erdős–Rényi graphs. This computation exploits the graph symmetry using the methodology introduced in [E. de Klerk, D.V. Pasechnik and A. Schrijver, Reduction of symmetric semidefinite programs using the regular *-representation, Math. Program. B 109 (2–3) (2007) 613–624]. The computed values are strictly better than the Godsil–Newman eigenvalue bounds.
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spelling ntu-10356/945382023-02-28T19:39:30Z On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs Sotirov, R. Klerk, Etienne de. Newman, M. W. Pasechnik, Dmitrii V. School of Physical and Mathematical Sciences DRNTU::Science::Mathematics We consider k-regular graphs with loops, and study the Lovász ϑ-numbers and Schrijver ϑ′-numbers of the graphs that result when the loop edges are removed. We show that the ϑ-number dominates a recent eigenvalue upper bound on the stability number due to Godsil and Newman [C.D. Godsil and M.W. Newman. Eigenvalue bounds for independent sets, J. Combin. Theory B 98 (4) (2008) 721–734]. As an application we compute the ϑ and ϑ′ numbers of certain instances of Erdős–Rényi graphs. This computation exploits the graph symmetry using the methodology introduced in [E. de Klerk, D.V. Pasechnik and A. Schrijver, Reduction of symmetric semidefinite programs using the regular *-representation, Math. Program. B 109 (2–3) (2007) 613–624]. The computed values are strictly better than the Godsil–Newman eigenvalue bounds. Accepted version 2012-02-07T05:51:32Z 2019-12-06T18:57:39Z 2012-02-07T05:51:32Z 2019-12-06T18:57:39Z 2008 2008 Journal Article Klerk, E. D., Newman, M. W., Pasechnik, D. V. & Sotirov R. (2009). On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs. European Journal of Combinatorics, 30(4), 879–888 https://hdl.handle.net/10356/94538 http://hdl.handle.net/10220/7516 10.1016/j.ejc.2008.07.022 en European journal of combinatorics © 2008 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by European Journal of Combinatorics, Elsevier.  It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document.  The published version is available at: [DOI: http://dx.doi.org/10.1016/j.ejc.2008.07.022 ] 16 p. application/pdf
spellingShingle DRNTU::Science::Mathematics
Sotirov, R.
Klerk, Etienne de.
Newman, M. W.
Pasechnik, Dmitrii V.
On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs
title On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs
title_full On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs
title_fullStr On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs
title_full_unstemmed On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs
title_short On the Lovász ϑ-number of almost regular graphs with application to Erdős–Rényi graphs
title_sort on the lovasz ϑ number of almost regular graphs with application to erdos renyi graphs
topic DRNTU::Science::Mathematics
url https://hdl.handle.net/10356/94538
http://hdl.handle.net/10220/7516
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