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sum of two squares

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The sum of two squares refers to a mathematical expression where a number can be represented as the sum of the squares of two integers. This concept is significant in number theory, particularly in the study of quadratic forms and the characterization of integers that can be expressed in this form.
lightbulbAbout this topic
The sum of two squares refers to a mathematical expression where a number can be represented as the sum of the squares of two integers. This concept is significant in number theory, particularly in the study of quadratic forms and the characterization of integers that can be expressed in this form.

Key research themes

1. How can prime factorization and representations as sums of squares interrelate to improve factorization and cryptographic analysis?

This theme explores the representation of semi-prime numbers as sums of squares and how such representations might offer more efficient prime factorization methods, which is significant for testing the security of cryptographic algorithms like RSA. By understanding the decomposition of semi-primes into sums of two or four squares, researchers investigate new factorization approaches that could impact cryptanalysis.

Key finding: This paper proposes an improved factorization method specific to semi-prime numbers composed of Pythagorean primes, demonstrating that the product of two such primes can be represented as the sum of four squares and uses... Read more
Key finding: The authors derive explicit formulas generating pairs of primitive Pythagorean triples sharing a common leg, enabling identification of semi-primes as products of odd primes involved in these triples. This mathematical... Read more
Key finding: Although primarily combinatorial, this work's construction of orthogonal Latin squares of specific orders underpins the algebraic structures essential for decompositions related to sums of squares, indirectly facilitating... Read more

2. What are the new mathematical identities and inequalities involving sums of squares and related ternary/quadratic forms?

Focused on theoretical advances in number theory, this theme investigates new identities for counting representations of integers as sums of three or two squares utilizing ternary quadratic forms, Watson's transformations, and Siegel–Weil formulas. It offers refined characterizations of representation counts and arithmetic structures underpinning the sums of squares problem.

Key finding: The paper proves a novel identity for s(np^2)−p*s(n), associating representation counts of integers as sums of three squares with ternary quadratic forms and employing Siegel–Weil and Smith–Minkowski formulas, significantly... Read more
Key finding: This work refines the understanding of digit sums in different bases, especially base 2, and their relation to squares, providing asymptotic bounds and density results. Although focusing on sum-of-digits functions, its... Read more
Key finding: By characterizing natural density and explicit forms of integers representable as sums of three squares drawn from binary partition functions, the paper relates 2-adic valuations and combinatorial partition structures to... Read more

3. How can semidefinite programming and polynomial optimization facilitate the decomposition of sums of squares and applications to system stability?

This research direction develops convex optimization methods such as SOS (sum of squares) decomposition and semidefinite programming (SDP) to certify polynomial positivity, decompose polynomials into sums of squares, and apply these techniques to analyze stability of nonlinear systems and design filters. This computational approach bridges algebraic theory with numerical methods for proofs and control.

Key finding: The paper formalizes SOS decomposition techniques to prove polynomial positivity efficiently using semidefinite programming, and demonstrates applications in nonlinear system stability analysis, including Lyapunov function... Read more
Key finding: This work formulates one-dimensional quadratic integral inequalities as function matrix inequalities and uses polynomial positivity via SOS and SDP to analyze stability conditions in PDE systems, providing a numerical... Read more
Key finding: The paper derives new upper and lower bounds on the Pythagoras number (minimum number of squares needed) for sums of square magnitudes of Laurent polynomials, leveraging properties of associated quadratic polynomial systems,... Read more
Key finding: Introducing a convex optimization framework to find polynomials whose certain linear combinations are non-negative, this study reformulates filter design problems as polynomial positivity problems solvable via semidefinite... Read more

All papers in sum of two squares

Seven wood sorption models available in the literature were parameterized for prediction of equilibrium moisture content for temperatures up to 220ºC. The criterion used to evaluate the models is the uncorrected sum of squares of... more
We initiate a direction for proving lower bounds on the size of non-commutative arithmetic circuits. This direction is based on a connection between lower bounds on the size of non-commutative arithmetic circuits and a problem about... more
The minimum sum-of-squared error clustering problem is shown to be a concave continuous optimization problem whose every local minimum solution must be integer. We characterize its local minima. A procedure of moving from a fractional... more
The minimum-sum-of-squared error clustering (MSSC) is one of the most intuitive and popular clustering algorithms. In this paper, we first show that MSSC can be equivalently cast as a concave minimization problem. To find the global... more
O caminho percorrido foi longo e grandes foram as dificuldades encontradas. Entretanto, com a colaboração de algumas pessoas, foi possível concluir este trabalho. Relaciono, a seguir, as pessoas a quem apresento meus mais sinceros... more
The theory of pseudo circle packings is developed. It generalizes the theory of circle packings. It allows the realization of almost any graph embedding by a geometric structure of circles. The corresponding Thurston's relaxation mapping... more
Mobile sensor networks are a great source of data. By collecting data with mobile sensor nodes from individuals in a user community, e.g. using their smartphones, we can learn global information such as traffic congestion patterns in the... more
Moving our hands smoothly is essential to execute ordinary tasks, such as carrying a glass of water without spilling. Past studies have revealed a natural tendency to generate smooth trajectories when moving the hand from one point to... more
Adem and Reichstein introduced the ideal of truncated symmetric polynomials to present the permutation invariant subring in the cohomology of a finite product of projective spaces. Building upon their work, I describe a generating set of... more
In this work we show that among all n-vertex graphs with edge or vertex connectivity k, ), the join of K k , the complete graph on k vertices, with the disjoint union of K 1 and K n-k-1 , is the unique graph with maximum sum of squares of... more
Complementarity problems may be formulated as nonlinear systems of equations with non-negativity constraints. The natural merit function is the sum of squares of the components of the system. Sufficient conditions are established which... more
Longitudinal stresses due to combined horizontal and vertical bending moments in ships, corresponding to a return period of 20 years, are estimated by linear response analysis. In principle, the stress should be obtained by combining the... more
Microaggregation for Statistical Disclosure Control (SDC) is a family of methods to protect microdata from individual identification. SDC seeks to protect microdata in such a way that can be published and mined without providing any... more
Joint regression analysis (JRA) is a popular method for analyzing genotype × environment (G × E) interactions, but multivariate techniques such as AMMI (additive main effects and multiplicative interaction) analysis have been recently... more
This paper addresses a new method to overcome the unmeasurable premise variables in TS nonlinear discrete time systems for observer design. It is known that a TS system can be obtained directly from a nonlinear one by using the sector... more
Abstract. The paper deals with a method for determining a switching combination of several local linear models using only the knowledge of the inputoutput data. The method is a direct optimisation of the sum of square errors between... more
Sugarcane (Saccharum sp.) is one of the most important crops in Brazil. The high demand for sugarcane-derived products has stimulated the expansion of sugarcane cultivation in recent years, exploring different environments. The... more
This work focuses on the computation of a candidate Lyapunov function for a Low Earth Orbit satellite which is actuated using only magnetorquers. A satellite having only electromagnetic actuation is not controllable when the magnetic... more
Genetic analysis of yield and morphological traits has been carried out in Coffea arabica from a half-diallel including the parental lines. The trial was established in west Cameroon with completely randomized single-tree plots.... more
Climate change studies based only on raw long-term data are potentially flawed due to the many breaks introduced from non-climatic sources, consequently quality controlled and homogenised climate data is desirable for basing climate... more
Magic, a key quantum resource beyond entanglement, remains poorly understood in terms of its structure and classification. In this paper, we demonstrate a striking connection between high-dimensional symmetric lattices and quantum magic... more
Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives... more
We follow a stream of the history of positive matrices and positive functionals, as applied to algebraic sums of squares decompositions, with emphasis on the interaction between classical moment problems, function theory of one or several... more
Solution methods for the minimum sum-of-squares clustering (MSSC) problem are analyzed and developed in this paper. Based on the DCA (Difference-of-Convex functions Algorithms) in DC programming and recently established qualitative... more
This study aims to present a comparative analysis of the Bayesian regularization backpropagation and Levenberg–Marquardt training algorithms in neural networks for the metrics prediction of damaged archaeological artifacts, of which the... more
In many quality control studies the performance of a product or process is usually characterized by a singleresponse variable However, in some applications of quality control, the performance of a product or aprocess can be best... more
Let K be a totally real number field with Galois closure L. We prove that if Moreover, our argument is constructive and generalizes to the case of commutative K-algebras. This result gives a partial resolution to a question of Sturmfels... more
Suppose f is a real univariate polynomial of degree D with exactly 4 monomial terms. We present an algorithm, with complexity polynomial in log D on average (relative to the stable log-uniform measure), for counting the number of real... more
Let K be a totally real number field with Galois closure L. We prove that if Moreover, our argument is constructive and generalizes to the case of commutative K-algebras. This result gives a partial resolution to a question of Sturmfels... more
Assessing the adaptability and stability of promising rice genotypes is one of the important steps for accurate evaluation. This study determined the genotype × environment interaction (GEI) and stability performance of 12 promising rice... more
Abstract. Using Howe duality we compute explicitly Kostant-type homology groups for a wide class of representations of the infinite-dimensional Lie superalgebra b gl ∞| ∞ and its classical subalgebras at positive integral levels. We also... more
The construction of asymptotically distribution free time series model specification tests using as statistics the estimated residual autocorrelations is considered from a general view point. We focus our attention on Box-Pierce type... more
Let <f>(x,y) be an integral binary quadratic form. A short proof is given of Pall's formula for the number of representations of <l>(x, y) as the sum of squares of two integral linear forms.
This paper describes a Matlab-based interactive tool focused on the modeling and control of nonlinear systems using a Takagi-Sugeno (T-S) fuzzy approach. Noticeably the modeling of dynamical nonlinear systems plays a fundamental role in... more
A new adaptive orthogonal search (AOS) algorithm is proposed for model subset selection and nonlinear system identification. Model structure detection is a key step in any system identification problem. This consists of selecting... more
A new adaptive orthogonal search (AOS) algorithm is proposed for model subset selection and nonlinear system identification. Model structure detection is a key step in any system identification problem. This consists of selecting... more
A method for the simultaneous co-registration and georeferencing of multiple 3D pointclouds and associated intensity information is proposed. It is a generalization of the 3D surface matching problem. The simultaneous co-registration... more
We present an algorithm for the least squares matching of overlapping 3D surfaces. It estimates the transformation parameters between two or more fully 3D surfaces, using the Generalized Gauss-Markoff model, minimizing the sum of squares... more
The automatic co-registration of point clouds, representing 3D surfaces, is a relevant problem in 3D modeling. This multiple registration problem can be defined as a surface matching task. We treat it as least squares matching of... more
We present fast new algorithms for evaluating trees with respect to least squares and minimum evolution (ME), the most commonly used criteria for inferring phylogenetic trees from distance data. The new algorithms include an optimal O(N 2... more
We present a solution of the operator-valued Schur-function realization problem on the right-half plane by developing the corresponding de Branges-Rovnyak canonical conservative simple functional model. This model corresponds to the... more
A facility has to be located within a given region taking two criteria of equity and efficiency into account. Equity is sought by minimizing the inequality in the inhabitant-facility distances, as measured by the sum of the absolute... more
The use of curve fitting for the analysis and interpretation of voltammetric data obtained while working with micro electrodes is discussed as a useful exercise for introducing students to the principle of problem solving using... more
In this paper, estimation of the linear regression model is made by ordinary least squares method and the partially linear regression model is estimated by penalized least squares method using smoothing spline. Then, it is investigated... more
In this paper, estimation of the linear regression model is made by ordinary least squares method and the partially linear regression model is estimated by penalized least squares method using smoothing spline. Then, it is investigated... more
In recent years using symmetry has proven to be a very useful tool to simplify computations in semidefinite programming. This dissertation examines the possibilities of exploiting discrete symmetries in three contexts: In SDP-based... more
Polya&#39;s fundamental enumeration theorem and some results from Williamson&#39;s generalized setup of it are proved in terms of Schur- Macdonald&#39;s theory (S-MT) of &quot;invariant matrices&quot;. Given a permutation group W ≤ Sd and... more
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