Tootfinder

Performance of the Extended Ising Machine for the Quadratic Knapsack Problem
Haruka Akishima, Hirotaka Tamura, Kazue Kudo
https://arxiv.org/abs/2508.06909 https://

Performance of the Extended Ising Machine for the Quadratic Knapsack Problem
The extended Ising machine (EIM) enhances conventional Ising models, which handle only binary quadratic forms by allowing constraints through real-valued dependent variables. We address the quadratic knapsack problem (QKP), hard to solve using Ising machines when formulated as a quadratic unconstrained binary optimization (QUBO). We demonstrated the EIM's superiority by comparing it with the conventional Ising model-based approach, a commercial exact solver, and a state-of-the-art heuristic sol…

Sparse Signal Recovery From Quadratic Systems with Full-Rank Matrices
Jinming Wen, Yi Hu, Meng Huang
https://arxiv.org/abs/2507.07557 https://

Sparse Signal Recovery From Quadratic Systems with Full-Rank Matrices
In signal processing and data recovery, reconstructing a signal from quadratic measurements poses a significant challenge, particularly in high-dimensional settings where measurements $m$ is far less than the signal dimension $n$ (i.e., $m \ll n$). This paper addresses this problem by exploiting signal sparsity. Using tools from algebraic geometry, we derive theoretical recovery guarantees for sparse quadratic systems, showing that $m\ge 2s$ (real case) and $m\ge 4s-2$ (complex case) generic me…

Relaxations of KKT Conditions do not Strengthen Finite RLT and SDP-RLT Bounds for Nonconvex Quadratic Programs
E. Alper Yildirim
https://arxiv.org/abs/2506.09892

Relaxations of KKT Conditions do not Strengthen Finite RLT and SDP-RLT Bounds for Nonconvex Quadratic Programs
We consider linear and semidefinite programming relaxations of nonconvex quadratic programs given by the reformulation-linearization technique (RLT relaxation), and the Shor relaxation combined with the RLT relaxation (SDP-RLT relaxation). By incorporating the first-order optimality conditions, a quadratic program can be formulated as an optimization problem with complementarity constraints. We investigate the effect of incorporating optimality conditions on the strength of the RLT and SDP-RLT …

Efficient Implementation of a Single-Qutrit Gate Set via Coherent Control
Xiang-Min Yu, Xiang Deng, Wen Zheng, Wei Xin, Tao Zhang, Hanxin Che, Kun Zhou, Haoyu Zhou, Yangyang Ge, Zhenchuan Zhang, Wanli Huang, Haoyang Cai, Xianke Li, Jie Zhao, Xinsheng Tan, Yu Zhang, Shao-Xiong Li, Yang Yu
https://arxiv.org/abs/2507.06860

Efficient Implementation of a Single-Qutrit Gate Set via Coherent Control
Qutrit offers the potential for enhanced quantum computation by exploiting an enlarged Hilbert space. However, the synthesis of high-fidelity and fast qutrit gates, particularly for single qutrit, remains an ongoing challenge, as it involves overcoming intrinsic constraints in quantum platforms. Here, we develop a novel framework for the efficient implementation of a single-qutrit gate set via coherent control, leveraging SU(3) dynamics while obviating platform-specific constraints such as aris…

Machine Learning-based quadratic closures for non-intrusive Reduced Order Models
Gabriele Codega, Anna Ivagnes, Nicola Demo, Gianluigi Rozza
https://arxiv.org/abs/2506.09830

Machine Learning-based quadratic closures for non-intrusive Reduced Order Models
In the present work, we introduce a data-driven approach to enhance the accuracy of non-intrusive Reduced Order Models (ROMs). In particular, we focus on ROMs built using Proper Orthogonal Decomposition (POD) in an under-resolved and marginally-resolved regime, i.e. when the number of modes employed is not enough to capture the system dynamics. We propose a method to re-introduce the contribution of neglected modes through a quadratic correction term, given by the action of a quadratic operator…

Maximal curves with respect to quadratic extensions over finite fields
Yves Aubry (IMATH, I2M, UTLN), Fabien Herbaut (UCA INSPE, UniCA, IMATH), Julien Monaldi (IMATH)
https://arxiv.org/abs/2506.08603

Maximal curves with respect to quadratic extensions over finite fields
We propose a detailed study of a canonical bound which relates the numbers of rational points of a curve over a finite field with that over its quadratic extension. Alternative proofs which relate to the variance enable to complete the inequality in a symmetrical way and to obtain optimal refinements. We focus on the curves reaching the bound, which we call Diophantinemaximal curves. We provide different characterizations and stress natural links with the curves which attain the Ihara bound. As…

Solvability of the Korteweg-de Vries equation under meromorphic initial conditions by quadrature
Kazuyuki Yagasaki
https://arxiv.org/abs/2506.08046 https:/…

Solvability of the Korteweg-de Vries equation under meromorphic initial conditions by quadrature
We study the solvability of the Korteweg-de Vries equation under meromorphic initial conditions by quadrature when the inverse scattering transform (IST) is applied. It is a key to solve the Schrödinger equation appearing in the Lax pair in application of the IST. We show that the Schrödinger equation is always integrable in the sense of differential Galois theory, i.e., solvable by quadrature, if and only if the meromporphic potential is reflectionless, under the condition that the potential…

Renormalization of bosonic quadratic Hamiltonians involving rank-one perturbations
Thomas Gamet (UMPA-ENSL)
https://arxiv.org/abs/2506.08590 https://

Renormalization of bosonic quadratic Hamiltonians involving rank-one perturbations
In this article, we study the renormalization of a bosonic quadratic Hamiltonian with an ultraviolet divergence. The Hamiltonian is composed of the sum of a free energy and the square of the smeared field operator. We explicitly diagonalize the Hamiltonian via Bogoliubov transformations, and the diagonalized Hamiltonian is easier to study. We show a renormalization of both the energy and the coupling constant depending on the form factor of the interaction.

Linear-Quadratic Mean Field Games with Common Noise: A Direct Approach
Wenyu Cong, Jingtao Shi, Bingchang Wang
https://arxiv.org/abs/2508.07271 https://arx…

Linear-Quadratic Mean Field Games with Common Noise: A Direct Approach
This paper investigates a linear-quadratic mean field games problem with common noise, where the drift term and diffusion term of individual state equations are coupled with both the state, control, and mean field terms of the state, and we adopt the direct approach to tackle this problem. Compared with addressing the corresponding mean field teams problem, the mean field games problem with state coupling presents greater challenges. This is not only reflected in the explosive increase in the n…

Turnpike Property of Stochastic Linear-Quadratic Optimal Control Problems in Large Horizons with Regime Switching I: Homogeneous Cases
Hongwei Mei, Rui Wang, Jiongmin Yong
https://arxiv.org/abs/2506.09337

Turnpike Property of Stochastic Linear-Quadratic Optimal Control Problems in Large Horizons with Regime Switching I: Homogeneous Cases
This paper is concerned with optimal control problems for a linear homogeneous stochastic differential equation having regime switching with purely quadratic functional in the large time horizons. We establish the so-called turnpike properties for the optimal pairs. The key is to prove a proper convergence of the solutions to the differential Riccati equations to the algebraic Riccati equation. Even for the problems without regime switchings, our result provides a refined estimate compared to t…