scholarly journals Upper bounds on algebraic connectivity via convex optimization

2006 ◽  
Vol 418 (2-3) ◽  
pp. 693-707 ◽  
Author(s):  
Arpita Ghosh ◽  
Stephen Boyd
Author(s):  
Yi Xu ◽  
Zhuoning Yuan ◽  
Sen Yang ◽  
Rong Jin ◽  
Tianbao Yang

Extrapolation is a well-known technique for solving convex optimization and variational inequalities and recently attracts some attention for non-convex optimization. Several recent works have empirically shown its success in some machine learning tasks. However, it has not been analyzed for non-convex minimization and there still remains a gap between the theory and the practice. In this paper, we analyze gradient descent  and stochastic gradient descent with extrapolation for finding an approximate first-order stationary point in smooth non-convex optimization problems. Our convergence upper bounds show that the algorithms with extrapolation can be accelerated than without extrapolation.


2009 ◽  
Vol 02 (01) ◽  
pp. 71-76 ◽  
Author(s):  
Lihua Feng ◽  
Guihai Yu ◽  
Xiqin Lin

In this paper, we study the Laplacian eigenvalues of graphs on n vertices with domination number γ and present upper bounds for the Laplacian spectral radius and algebraic connectivity as well, which improve old results apparently.


Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 387
Author(s):  
Hamza Fawzi ◽  
Omar Fawzi

We introduce a new quantum Rényi divergence Dα# for α∈(1,∞) defined in terms of a convex optimization program. This divergence has several desirable computational and operational properties such as an efficient semidefinite programming representation for states and channels, and a chain rule property. An important property of this new divergence is that its regularization is equal to the sandwiched (also known as the minimal) quantum Rényi divergence. This allows us to prove several results. First, we use it to get a converging hierarchy of upper bounds on the regularized sandwiched α-Rényi divergence between quantum channels for α>1. Second it allows us to prove a chain rule property for the sandwiched α-Rényi divergence for α>1 which we use to characterize the strong converse exponent for channel discrimination. Finally it allows us to get improved bounds on quantum channel capacities.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Yan Sun ◽  
Faxu Li

It is well known that the algebraic connectivity of a graph is the second small eigenvalue of its Laplacian matrix. In this paper, we mainly research the relationships between the algebraic connectivity and the disjoint vertex subsets of graphs, which are presented through some upper bounds on algebraic connectivity.


2020 ◽  
Vol 12 (02) ◽  
pp. 2050022
Author(s):  
Ruhul Amin ◽  
Sk. Md. Abu Nayeem

The Kirchhoff index and Laplacian-energy-like invariant of a connected graph [Formula: see text], denoted by [Formula: see text] and [Formula: see text], are given by the number of vertex times the sum of the reciprocals of all nonzero Laplacian eigenvalues of [Formula: see text] and the sum of the square roots of all Laplacian eigenvalues of [Formula: see text], respectively. In this paper, we have obtained the Laplacian eigenvalues of some derived graphs, such as double graph, extended double cover and Mycielskian of an [Formula: see text]-regular graph [Formula: see text], in terms of the adjacency eigenvalues of [Formula: see text] and hence, we obtain some upper bounds of Kirchhoff index and Laplacian-energy-like (LEL) invariant of those derived graphs in terms of [Formula: see text], number of vertices and algebraic connectivity of [Formula: see text]. We have shown that the bounds obtained here are better than some existing bounds. We have also obtained the exact formulae for Kirchhoff index and LEL invariant of those derived graph when [Formula: see text] is a complete graph or a complete bipartite graph.


Author(s):  
Stephen Boyd ◽  
Lieven Vandenberghe
Keyword(s):  

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