Results 81 to 90 of about 6,081 (225)

A paradox in bosonic energy computations via semidefinite programming relaxations

New Journal of Physics, 2013
We show that the recent hierarchy of semidefinite programming relaxations based on non-commutative polynomial optimization and reduced density matrix variational methods exhibits an interesting paradox when applied to the bosonic case: even though it can
M Navascués, A García-Sáez, A Acín, S Pironio, M B Plenio   +4 more
doaj   +1 more source

Oppenheim–Schur inequalities for causal products

Bulletin of the London Mathematical Society, Volume 58, Issue 6, June 2026.
Abstract We establish a class of Oppenheim–Schur‐type inequalities for the convolutional Jury product of positive semidefinite matrices. These results extend the classical Schur and Oppenheim inequalities associated with the Hadamard product to a causal convolutional setting.
Dominique Guillot, Javad Mashreghi, Prateek Kumar Vishwakarma   +2 more
wiley   +1 more source

Enabling Stochastic Dynamic Games for Robotic Swarms

Advanced Intelligent Systems, Volume 8, Issue 5, May 2026.
This paper scales stochastic dynamic games to large swarms of robots through selective agent modeling and variable partial belief space planning. We formulate these games using a belief space variant of iterative Linear Quadratic Gaussian (iLQG). We scale to teams of 50 agents through selective modeling based on the estimated influence of agents ...
Kamran Vakil, Alyssa Pierson
wiley   +1 more source

Correcting for finite statistics effects in a quantum steering experiment

Physical Review Research
Verifying entanglement between parties is essential for creating secure quantum communication. However, finite statistics can lead to false positive outcomes in any tests for entanglement.
Sophie Engineer, Ana C. S. Costa, Alexandre C. Orthey, Jr., Xiaogang Qiang, Jianwei Wang, Jeremy L. O'Brien, Jonathan C. F. Matthews, Will McCutcheon, Roope Uola, Sabine Wollmann   +9 more
doaj   +1 more source

Spatial Image Gradient Estimation From the Diffusion MRI Profile

Magnetic Resonance in Medicine, Volume 95, Issue 5, Page 2980-2991, May 2026.
ABSTRACT Purpose In the course of diffusion, water molecules encounter varying values for the relaxation‐time properties of the underlying tissue. This factor, which has rarely been accounted for in diffusion MRI (dMRI), is modeled in this work, allowing for the estimation of the gradient of relaxation‐time properties from the dMRI signal. Methods With
Iman Aganj, Thorsten Feiweier, John E. Kirsch, Bruce R. Fischl, Andre J. van der Kouwe   +4 more
wiley   +1 more source

A note on set-semidefinite relaxations of nonconvex quadratic programs [PDF]

, 2013
We consider semidefinite, copositive, and more general, set-semidefinite programming relaxations of general nonconvex quadratic problems. For the semidefinite case a comparison between the feasible set of the original program and the feasible set of the ...
Ahmed, F., Still, Georg J.
core   +1 more source

Semidefinite relaxation detector for higher-order modulated multiple-antenna systems

Tongxin xuebao, 2007
A semidefinite relaxation detector of 64-QAM signals was proposed,which is derived from rank relaxation and Lagrange bidual programming respectively.Computational complexity analyses and simulation results demonstrate the detector can make a good ...
YANG Yi-jin, ZHAO Chun-ming, XU Wei, ZHOU Peng   +3 more
doaj   +2 more sources

Entrywise transforms preserving matrix positivity and nonpositivity

Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.
Abstract We characterize real and complex functions which, when applied entrywise to square matrices, yield a positive definite matrix if and only if the original matrix is positive definite. We refer to these transformations as sign preservers. Compared to the classical work on entrywise preservers by Schoenberg and others, we completely resolve this ...
Dominique Guillot, Himanshu Gupta, Prateek Kumar Vishwakarma, Chi Hoi Yip   +3 more
wiley   +1 more source

Array pattern synthesis using semidefinite programming and a bisection method

ETRI Journal, 2019
In this paper, we propose an array pattern synthesis scheme using semidefinite programming (SDP) under array excitation power constraints. When an array pattern synthesis problem is formulated as an SDP problem, it is known that an additional rank‐one ...
Jong‐Ho Lee, Jeongsik Choi, Woong‐Hee Lee, Jiho Song   +3 more
doaj   +1 more source

Exploiting Sparsity in SDP Relaxation for Harmonic Balance Method

IEEE Access, 2020
In general, harmonic balance problems are extremely nonconvex and difficult to solve. A convex relaxation in the form of semidefinite programming has attracted a lot of attention recently, as it finds a global solution with high accuracy without the need
Cheng-Hsiung Yang, Ben Shen Deng
doaj   +1 more source