J. William Helton

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All published works

Action	Title	Year	Authors
+ PDF Chat	Uniform Convergence of an Asymptotic Approximation to Associated Stirling Numbers	2024	E. Rodney Canfield J. William Helton Jared A. Hughes
+ PDF Chat	Matrix extreme points and free extreme points of free spectrahedra	2024	Aidan Epperly Eric Evert J. William Helton Igor Klep
+ PDF Chat	Relaxations and Exact Solutions to Quantum Max Cut via the Algebraic Structure of Swap Operators	2024	Adam Bene Watts Anirban Chowdhury Aidan Epperly J. William Helton Igor Klep
+	Synchronous Values of Games	2024	J. William Helton Hamoon Mousavi Seyed Sajjad Nezhadi Vern I. Paulsen Travis B. Russell
+ PDF Chat	3XOR Games with Perfect Commuting Operator Strategies Have Perfect Tensor Product Strategies and are Decidable in Polynomial Time	2023	Adam Bene Watts J. William Helton
+ PDF Chat	Noncommutative Nullstellensätze and Perfect Games	2023	Adam Bene Watts J. William Helton Igor Klep
+	Relaxations and Exact Solutions to Quantum Max Cut via the Algebraic Structure of Swap Operators	2023	Adam Bene Watts Anirban Chowdhury Aidan Epperly J. William Helton Igor Klep
+	Satisfiability Phase Transtion for Random Quantum 3XOR Games	2022	Adam Bene Watts J. William Helton Zehong Zhao
+	Matrix Extreme Points and Free extreme points of Free spectrahedra	2022	Aidan Epperly Eric Evert J. William Helton Igor Klep
+ PDF Chat	Noncommutative Nullstellens\"atze and Perfect Games	2021	Adam Bene Watts J. William Helton Igor Klep
+	Efficient evaluation of noncommutative polynomials using tensor and noncommutative Waring decompositions.	2021	Eric Evert J. William Helton Shiyuan Huang Jiawang Nie
+ PDF Chat	Empirical Properties of Optima in Free Semidefinite Programs	2021	Eric Evert Yi Fu J. William Helton John Yin
+	Synchronous Values of Games	2021	J. William Helton Hamoon Mousavi Seyed Sajjad Nezhadi Vern I. Paulsen Travis B. Russell
+	Noncommutative Nullstellensätze and Perfect Games	2021	Adam Bene Watts J. William Helton Igor Klep
+ PDF Chat	Efficient Evaluation of Noncommutative Polynomials Using Tensor and Noncommutative Waring Decompositions	2020	Eric Evert J. William Helton Shiyuan Huang Jiawang Nie
+ PDF Chat	Plurisubharmonic noncommutative rational functions	2020	Harry Dym J. William Helton Igor Klep Scott McCullough Jurij Volčič
+ PDF Chat	Noncommutative Polynomials Describing Convex Sets	2020	J. William Helton Igor Klep Scott McCullough Jurij Volčič
+	Empirical properties of optima in free semidefinite programs	2020	Eric Evert Yi Fu J. William Helton John Yin
+ PDF Chat	Factorization of Noncommutative Polynomials and Nullstellensätze for the Free Algebra	2020	J. William Helton Igor Klep Jurij Volčič
+	Bianalytic free maps between spectrahedra and spectraballs	2020	J. William Helton Igor Klep Scott McCullough Jurij Volčič
+	3XOR Games with Perfect Commuting Operator Strategies Have Perfect Tensor Product Strategies and are Decidable in Polynomial Time	2020	Adam Bene Watts J. William Helton
+	Factorization of noncommutative polynomials and Nullstellens\"atze for the free algebra	2019	J. William Helton Igor Klep Jurij Volčič
+ PDF Chat	Arveson extreme points span free spectrahedra	2019	Eric Evert J. William Helton
+	The noncommutative Waring problem	2019	Eric Evert J. William Helton Shiyuan Huang Jiawang Nie
+ PDF Chat	Free Bianalytic Maps between Spectrahedra and Spectraballs in a Generic Setting	2019	Meric Augat J. William Helton Igor Klep Scott McCullough
+ PDF Chat	Dilations, Linear Matrix Inequalities, the Matrix Cube Problem and Beta Distributions	2019	J. William Helton Igor Klep Scott McCullough Markus Schweighofer
+	Arveson extreme points span free spectrahedra	2018	Eric Evert J. William Helton
+	Geometry of free loci and factorization of noncommutative polynomials	2018	J. William Helton Igor Klep Jurij Volčič
+ PDF Chat	Bianalytic maps between free spectrahedra	2018	Meric Augat J. William Helton Igor Klep Scott McCullough
+ PDF Chat	Applications of realizations (aka linearizations) to free probability	2017	J. William Helton Tobias Mai Roland Speicher
+ PDF Chat	Extreme Points of Matrix Convex Sets, Free Spectrahedra, and Dilation Theory	2017	Eric Evert J. William Helton Igor Klep Scott McCullough
+ PDF Chat	The tracial Hahn–Banach theorem, polar duals, matrix convex sets, and projections of free spectrahedra	2017	J. William Helton Igor Klep Scott McCullough
+ PDF Chat	Non-Commutative Polynomials with Convex Level Slices	2017	Harry Dym J. William Helton Scott McCullough
+	Free bianalytic maps between spectrahedra and spectraballs in a generic setting	2017	Meric Augat J. William Helton Igor Klep Scott McCullough
+ PDF Chat	Convex Entire Noncommutative Functions are Polynomials of Degree Two or Less	2016	J. William Helton J. E. Pascoe Ryan Tully‐Doyle Victor Vinnikov
+	Circular free spectrahedra	2016	Eric Evert J. William Helton Igor Klep Scott McCullough
+	Changing noncommuting variables with free analytic functions	2016	J. William Helton
+	Non-commutative polynomials with convex level slices	2015	Harry Dym J. William Helton Scott McCullough
+	Applications of Realizations (aka Linearizations) to Free Probability	2015	J. William Helton Tobias Mai Roland Speicher
+ PDF Chat	Matrix convex hulls of free semialgebraic sets	2015	J. William Helton Igor Klep Scott McCullough
+ PDF Chat	Real nullstellensatz and -ideals in -algebras	2015	Jaka Cimprič J. William Helton Scott McCullough Christopher Nelson
+	Convex entire noncommutative functions are polynomials of degree two or less	2015	J. William Helton J. E. Pascoe Ryan Tully‐Doyle Victor Vinnikov
+	Convex entire noncommutative functions are polynomials of degree two or less	2015	J. William Helton J. E. Pascoe Ryan Tully‐Doyle Victor Vinnikov
+	Non-commutative polynomials with convex level slices	2015	Harry Dym J. William Helton Scott McCullough
+	Applications of Realizations (aka Linearizations) to Free Probability	2015	J. William Helton Tobias Mai Roland Speicher
+	Dilations, Linear Matrix Inequalities, the Matrix Cube Problem and Beta Distributions	2014	J. William Helton Igor Klep Scott McCullough Markus Schweighofer
+	Inclusion of spectrahedra, dilations, the matrix cube problem and coin tossing	2014	J. William Helton Igor Klep Scott McCullough Markus Schweighofer
+	Free semidefinite representation of matrix power functions	2014	J. William Helton Jiawang Nie Jeremy S. Semko
+	Noncommutative polynomials nonnegative on a variety intersect a convex set	2014	J. William Helton Igor Klep Christopher Nelson
+	Dilations, Linear Matrix Inequalities, the Matrix Cube Problem and Beta Distributions	2014	J. William Helton Igor Klep Scott McCullough Markus Schweighofer
+ PDF Chat	NON-COMMUTATIVE REPRESENTATIONS OF FAMILIES OF k<sup>2</sup> COMMUTATIVE POLYNOMIALS IN 2k<sup>2</sup> COMMUTING VARIABLES	2013	Harry Dym J. William Helton Caleb Meier
+ PDF Chat	On real one-sided ideals in a free algebra	2013	Jakob Cimprič J. William Helton Igor Klep Scott McCullough Christopher Nelson
+	Free Semidefinite Representation of Matrix Power Functions	2013	J. William Helton Jiawang Nie Jeremy S. Semko
+	Free Convex Algebraic Geometry	2013	J. William Helton Igor Klep Scott McCullough
+	Free Semidefinite Representation of Matrix Power Functions	2013	J. William Helton Jiawang Nie Jeremy S. Semko
+	Non-Commutative Representations of Families of k^2 Commutative Polynomials in 2k^2 Commuting Variables	2012	Harry Dym J. William Helton Caleb Meier
+ PDF Chat	A noncommutative real nullstellensatz corresponds to a noncommutative real ideal: Algorithms	2012	Jakob Cimprič J. William Helton Scott McCullough Christopher Nelson
+	Chapter 8: Free Convex Algebraic Geometry	2012	J. William Helton Igor Klep Scott McCullough
+ PDF Chat	A Semidefinite Approach for Truncated K-Moment Problems	2012	J. William Helton Jiawang Nie
+ PDF Chat	Every convex free basic semi-algebraic set has an LMI representation	2012	J. William Helton Scott McCullough
+	The convex Positivstellensatz in a free algebra	2012	J. William Helton Igor Klep Scott McCullough
+ PDF Chat	The matricial relaxation of a linear matrix inequality	2012	J. William Helton Igor Klep Scott McCullough
+	Non-commutative varieties with curvature having bounded signature	2012	Harry Dym J. William Helton Scott McCullough
+	Free convex sets defined by rational expressions have LMI representations	2012	J. William Helton Scott McCullough
+ PDF Chat	Free Analysis, Convexity and LMI Domains	2012	J. William Helton Igor Klep Scott McCullough
+ PDF Chat	The possible shapes of numerical ranges	2012	J. William Helton Ilya M. Spitkovsky
+	Free analysis, convexity and LMI domains	2012	J. William Helton Igor Klep Scott McCullough
+	Non-commutative varieties with curvature having bounded signature	2012	Harry Dym J. William Helton Scott McCullough
+ PDF Chat	Semidefinite programming in matrix unknowns which are dimension free	2011	J. William Helton Igor Klep Scott McCullough
+	Semidefinite Representation of Convex Sets and Convex Hulls	2011	J. William Helton Jiawang Nie
+ PDF Chat	Convexity and Semidefinite Programming in Dimension-Free Matrix Unknowns	2011	J. William Helton Igor Klep Scott McCullough
+	Noncommutative plurisubharmonic polynomials part I: Global assumptions	2011	Jeremy M. Greene J. William Helton Victor Vinnikov
+	The possible shapes of numerical ranges	2011	J. William Helton Ilya M. Spitkovsky
+	A Semidefinite Approach for Truncated K-Moment Problems	2011	J. William Helton Jiawang Nie
+	Non-commutative varieties with curvature having bounded signature	2011	Harry Dym J. William Helton Scott McCullough
+	The possible shapes of numerical ranges	2011	J. William Helton Ilya M. Spitkovsky
+	Noncommutative Plurisubharmonic Polynomials Part I: Global Assumptions	2011	Jeremy M. Greene J. William Helton Victor Vinnikov
+	Solvability of linear matrix equations in a symmetric matrix variable	2010	Maurı́cio C. de Oliveira J. William Helton
+	Relaxing LMI domination matricially	2010	J. William Helton Igor Klep Scott McCullough
+	Analytic mappings between noncommutative pencil balls	2010	J. William Helton Igor Klep Scott McCullough
+	Proper analytic free maps	2010	J. William Helton Igor Klep Scott McCullough
+	Topics in Operator Theory	2010	Joseph A. Ball Vladimir Bolotnikov Leiba Rodman J. William Helton Ilya M. Spitkovsky
+	The XIXth international workshop on operator theory and its applications. II	2010	Joseph A. Ball Vladimir Bolotnikov J. William Helton Leiba Rodman Ilya M. Spitkovsky
+	Proceedings of the XIXth international workshop on operator theory and its applications, college of William and Mary, 2008	2010	Joseph A. Ball Vladimir Bolotnikov J. William Helton Leiba Rodman Ilya M. Spitkovsky
+	Systems and mathematical physics	2010	Joseph A. Ball Vladimir Bolotnikov J. William Helton Leiba Rodman Ilya M. Spitkovskiĭ
+	Operators, matrices and analytic functions : proceedings of the XIXth International Workshop on Operator Theory and its Applications, College of William and Mary, 2008	2010	Joseph A. Ball Vladimir Bolotnikov J. William Helton Leiba Rodman Ilya M. Spitkovskiĭ
+	Every free basic convex semi-algebraic set has an LMI representation	2009	J. William Helton Scott McCullough
+	Every free basic semi-algebraic set has an LMI representation	2009	J. William Helton Scott McCullough
+ PDF Chat	Sign patterns for chemical reaction networks	2009	J. William Helton Vitaly Katsnelson Igor Klep
+ PDF Chat	Classification of all noncommutative polynomials whose Hessian has negative signature one and a noncommutative second fundamental form	2009	Harry Dym Jeremy M. Greene J. William Helton Scott McCullough
+	Convex Matrix Inequalities Versus Linear Matrix Inequalities	2009	J. William Helton Scott McCullough Mihai Putinar Victor Vinnikov
+	Noncommutative ball maps	2009	J. William Helton Igor Klep Scott McCullough Nick Slinglend
+ PDF Chat	Sufficient and Necessary Conditions for Semidefinite Representability of Convex Hulls and Sets	2009	J. William Helton Jiawang Nie
+	Classification of All Noncommutative Polynomials Whose Hessian Has Negative Signature One and A Noncommutative Second Fundamental Form	2009	Harry Dym Jeremy M. Greene J. William Helton Scott McCullough
+	Non-Commutative Harmonic and Subharmonic Polynomials	2009	J. William Helton Daniel P. McAllaster Joshua A. Hernandez
+ PDF Chat	Determinant Expansions of Signed Matrices and of Certain Jacobians	2009	J. William Helton Igor Klep Raul Gomez
+	Every free basic convex semi-algebraic set has an LMI representation	2009	J. William Helton Scott McCullough
+	Engineering Systems and Free Semi-Algebraic Geometry	2008	Maurı́cio C. de Oliveira J. William Helton Scott McCullough Mihai Putinar
+ PDF Chat	Homotopy methods for counting reaction network equilibria	2008	Gheorghe Crăciun J. William Helton Ruth Williams
+ PDF Chat	Semidefinite representation of convex sets	2008	J. William Helton Jiawang Nie
+ PDF Chat	Measures with zeros in the inverse of their moment matrix	2008	J. William Helton Jean B. Lasserre Mihai Putinar
+ PDF Chat	Non-Commutative Harmonic and Subharmonic Polynomials	2008	J. William Helton Daniel P. McAllaster Joshua A. Hernandez
+	Non-Commutative Partial Matrix Convexity	2008	Damon M. Hay J. William Helton Adrian P. C. Lim Scott McCullough
+	Conditions for a massless plasma analysis to predict stabilization of the tokamak plasma vertical instability	2008	J. William Helton Kevin J. McGown M.L. Walker
+ PDF Chat	Structured semidefinite representation of some convex sets	2008	J. William Helton Jiawang Nie
+	Structured Semidefinite Representation of Some Convex Sets	2008	J. William Helton Jiawang Nie
+ PDF Chat	Non-commutative partial matrix convexity	2008	Damon M. Hay J. William Helton Adrian P. C. Lim Scott McCullough
+	The Hessian of a noncommutative polynomial has numerous negative eigenvalues	2007	Harry Dym J. William Helton Scott McCullough
+	Multivariate moment matrices with zeros in their inverse	2007	J. William Helton Jean B. Lasserre Mihai Putinar
+	Irreducible noncommutative defining polynomials for convex sets have degree 4 or less	2007	Harry Dym J. William Helton Scott McCullough
+	Operator-valued Semicircular Elements: Solving A Quadratic Matrix Equation with Positivity Constraints	2007	J. William Helton Reza Rashidi Far Roland Speicher
+	Homotopy methods for counting reaction network equilibria	2007	Gheorghe Crăciun J. William Helton Ruth Williams
+	Sufficient and Necessary Conditions for Semidefinite Representability of Convex Hulls and Sets	2007	J. William Helton Jiawang Nie
+	Operator-valued semicircular elements: Solving a quadratic matrix equation with positivity constraints	2007	J. William Helton Reza Rashidi Far Roland Speicher
+	Semidefinite Representation of Convex Sets	2007	J. William Helton Jiawang Nie
+	Strong majorization in a free ✱-algebra	2006	J. William Helton Scott McCullough Mihai Putinar
+	Computer algebra tailored to matrix inequalities in control	2006	Maurı́cio C. de Oliveira J. William Helton
+ PDF Chat	Linear matrix inequality representation of sets	2006	J. William Helton Victor Vinnikov
+	Noncommutative convexity arises from linear matrix inequalities	2006	J. William Helton Scott McCullough Victor Vinnikov
+ PDF Chat	Matrix Representations for Positive Noncommutative Polynomials	2006	J. William Helton Scott McCullough Mihai Putinar
+	A Symbolic Procedure for Computing Semidefinite Program Duals	2006	Maurı́cio C. de Oliveira J. William Helton
+	Positive polynomials in scalar and matrix variables, the spectral theorem and optimization	2006	J. William Helton Mihai Putinar Tibi Constantinescu
+	Solving Matrix Inequalities whose Unknowns are Matrices	2006	Juan F. Camino J. William Helton Robert E. Skelton
+	SOLVING MATRIX INEQUALITIES WHOSE UNKNOWNS ARE	2006	Juan F. Camino J. William Helton Robert E. Skelton
+	Linear fractional parameterizations of matrix function spaces and a new proof of the Youla-Jabr-Bongiorno parameterization for stabilizing compensators	2005	Joseph A. Ball J. William Helton
+	H∞ - optimal feedback controllers for linear multivariable systems	2005	Bruce A. Francis J. William Helton G. Zames
+	H /sup ∞/ Optimization and Semidefinite Programming	2005	J. William Helton Orlando Merino Trent E. Walker
+	Conditions for optimality over H/sup infinity /: numerical algorithms	2005	J. William Helton Orlando Merino Trent E. Walker
+ PDF Chat	Extremal Problems of Interpolation Theory	2005	J. William Helton Lev Sakhnovich
+ PDF Chat	Non-negative hereditary polynomials in a free *−algebra	2005	J. William Helton Scott McCullough Mihai Putinar
+	NONCOMMUTATIVE CONVEXITY VS LMI'S	2005	J. William Helton Scott McCullough Victor Vinnikov
+	A positivstellensatz for non-commutative polynomials	2004	J. William Helton Scott McCullough
+ PDF Chat	A non-commutative Positivstellensatz on isometries	2004	J. William Helton Scott McCullough Mihai Putinar
+	Convex Noncommutative Polynomials Have Degree Two or Less	2004	J. William Helton Scott McCullough
+	Solving matrix inequalities whose unknowns are matrices	2004	Juan F. Camino J. William Helton Robert E. Skelton
+	Current Trends in Operator Theory and its Applications	2004	Joseph A. Ball J. William Helton Martin Klaus Leiba Rodman
+	Matrix Inequalities: A Symbolic Procedure to Determine Convexity Automatically	2003	Juan F. Camino J. William Helton Robert E. Skelton Jieping Ye
+	The Matrix Multidisk Problem	2003	Harry Dym J. William Helton
+	Algorithms for solving multidisk problems in H/sup ∞/ optimization	2003	Harry Dym J. William Helton Orlando Merino
+ PDF Chat	Noncommutative computer algebra in the control of singularly perturbed dynamical systems	2003	J. William Helton F. Dell Kronewitter Mark Stankus
+	H/sup infinity / control for nonlinear plants: connections with differential games	2003	Joseph A. Ball J. William Helton
+	Factorization of nonlinear systems: toward a theory for nonlinear H/sup infinity / control	2003	Joseph A. Ball J. William Helton
+	Manipulating Matrix Inequalities Automatically	2003	J. William Helton
+	Global Uniqueness Tests and Performance Bounds for \boldmath$H^\infty$ Optima	2003	J. William Helton Marshall A. Whittlesey
+	Linear Matrix Inequality Representation of Sets	2003	J. William Helton Victor Vinnikov
+	H/sup ∞/ optimization with time domain and other constraints	2002	J. William Helton Orlando Merino Trent E. Walker
+	Semidefinite programming tailored to H/sup ∞/ optimization arising from plant uncertainty problems	2002	J. William Helton Orlando Merino
+	ℋ/sup ∞/ optimization with uncertainty in the plant	2002	J. William Helton Orlando Merino Trent E. Walker
+ PDF Chat	Computer simplification of engineering systems formulas	2002	J. William Helton Mark Stankus John J. Wavrik
+	Sufficient conditions for optimization of matrix functions	2002	J. William Helton Orlando Merino
+	Numerical solution of nonlinear H/sub 2/ and H/sub ∞/ control problems with application to jet engine control	2002	Michael Hardt J. William Helton Kenneth Kreutz-Delgado
+	Coordinate optimization for bi-convex matrix inequalities	2002	J. William Helton Orlando Merino
+	A symbolic algorithm for determining convexity of a matrix function: how to get Schur complements out of your life	2002	Juan F. Camino J. William Helton Robert E. Skelton
+	"Positive" Noncommutative Polynomials Are Sums of Squares	2002	J. William Helton
+ PDF Chat	Multidisk problems in H Optimization: A method for analyzing numerical algorithms	2002	Harry Dym J. William Helton Orlando Merino
+	Multidisk Problems inH 1 Optimization: A Method for Analysing Numerical Algorithms	2002	Harry Dym J. William Helton Orlando Merino
+ PDF Chat	Some adaptive control problems which convert to a "classical" problem in several complex variables	2001	J. William Helton
+ PDF Chat	Singularly perturbed control systems using non‐commutative computer algebra	2000	J. William Helton F. Dell Kronewitter William M. McEneaney Mark Stankus
+ PDF Chat	Singularly perturbed control systems using non-commutative computer algebra	2000	J. William Helton F. Dell Kronewitter William M. McEneaney Mark Stankus
+	Design of Robust Controllers: Frequency Domain Methods and Their Non-Linear Extensions	1999	J. William Helton
+	H∞ optimization with plant uncertainty and semidefinite programming	1998	J. William Helton Orlando Merino Trent E. Walker
+	H optimization with plant uncertainty and semidefinite programming	1998	J. William Helton Orlando Merino Trent E. Walker
+	Classification of hereditary matrices	1998	Jim Agler J. William Helton Mark Stankus
+	Sufficient Conditions for Optimization of Matrix	1998	J. William Helton Orlando Merino
+	Classical control using H[∞] methods	1998	J. William Helton Orlando Merino
+	Piecewise Riccati equations and the bounded real lemma	1997	J. William Helton Wei Zhan
+	Analytic Functions Optimizing Competing Constraints	1997	J. William Helton Andrei E. Vityaev
+	On the stability of the information state system	1996	J. William Helton M. R. James
+	Non-minimal factorization of nonlinear systems: the observable case	1996	Asher Ben-Artzi J. William Helton Hugo J. Woerdeman
+	SOME SYSTEMS THEOREMS ARISING FROM THE BIEBERBACH CONJECTURE	1996	J. William Helton Frederick Weening
+	Optimization over analytic functions whose founrier coefficients are constrained	1995	J. William Helton Orlando Merino Trent E. Walker
+	Geometric Aspects of Functional Analysis	1995	Jonathan Arazy Aharon Atzmon Joseph A. Ball Blackburg Ben-Artzi Hari Bercovici Albrecht Böttcher L. A. Coburn Kenneth R. Davidson Robert J. Douglas Rehovot Dym
+	Sparsity Patterns with High Rank Extremal Positive Semidefinite Matrices	1994	J. William Helton D. J. Lam Hugo J. Woerdeman
+	Nonselfadjoint Operators and Related Topics	1994	Jonathan Arazy Aharon Atzmon Joseph A. Ball Blackburg Ben-Artzi Hari Bercovici Albrecht Böttcher L. A. Coburn Kenneth R. Davidson Robert J. Douglas Rehovot Dym
+	Conditions for Optimality over $H^\infty $	1993	J. William Helton Orlando Merino
+	Novel approach to accelerating Newton's method for sup-norm optimization arising inH ?-control	1993	J. William Helton Orlando Merino
+	Symmetric Hankel operators: minimal norm extensions and eigenstructures	1993	J. William Helton Hugo J. Woerdeman
+	Inner-outer factorization of nonlinear operators	1992	Joseph A. Ball J. William Helton
+	A factorization principle for stabilization of linear control systems	1991	Joseph A. Ball J. William Helton M.S. Verma
+ PDF Chat	Optimal analytic disks	1991	J. William Helton Orlando Merino
+	H [infinity]-control theory : lectures given at the 2nd session of the Centro internazionale matematico estivo (C.I.M.E.) held in Como, Italy, June 18-26, 1990	1991	Centro internazionale matematico estivo. Session Ciprian Foiaş E. Mosca Luciano Pandolfi Bruce A. Francis J. William Helton Huibert Kwakernaak J.B. Pearson
+	Tracking poles and representing Hankel operators directly from data	1990	J. William Helton P. G. Spain N. J. Young
+	Numerical results on H<sup>∞</sup> control	1990	J. William Helton Orlando Merino
+	The Riccati PDE's Associated with Invariant Distributions and Minimal Factorization of Systems	1990	Asher Ben-Artzi J. William Helton
+	Approximation of Hankel Operators: Truncation Error in an H ∞ Design Method	1990	J. William Helton N. J. Young
+	Nonlinear H ∞ Control Theory: A Literature Survey	1990	Joseph A. Ball J. William Helton
+	The Ranks of Extremal Positive Semidefinite Matrices with Given Sparsity Pattern	1989	J. William Helton Stephen Pierce Leiba Rodman
+	A Poincaré-Dulac approach to a nonlinear Beurling-Lax-Halmos theorem	1989	Joseph A. Ball Ciprian Foiaş J. William Helton Allen Tannenbaum
+	Frequency response algorithms for H/sub infinity / optimization with time domain constraints	1989	J. William Helton A. Sideris
+	Factorization and General Properties of Nonlinear Toeplitz Operators	1989	Joseph A. Ball J. William Helton
+	Factorization and General Properties of Nonlinear Toeplitz Operators	1989	Joseph A. Ball J. William Helton
+	Polynomially contractible sets	1988	J. William Helton David F. Schwartz
+	Shift invariant manifolds and nonlinear analytic function theory	1988	Joseph A. Ball J. William Helton
+	A numerical method for computing the structured singular value	1988	J. William Helton
+	Shift Invariant Subspaces, Passivity, Reproducing Kernels and H ∞-Optimization	1988	Joseph A. Ball J. William Helton
+	Contributions to operator theory and its applications : proceedings of the Conference on Operator Theory and Functional Analysis, Mesa, Arizona, June 11-14, 1987	1988	Israel Gohberg J. William Helton Leiba Rodman
+	Vandermonde and resultant matrices: An abstract approach	1987	J. William Helton Leiba Rodman
+	Well posedness of nonlinear casual feedback systems	1987	Joseph A. Ball J. William Helton
+	Local optima in h<sup>∞</sup> produce a constant objective function	1987	J. William Helton David F. Schwartz S. E. Warschawski
+	Nonlinear Interpolation Theory in H∞	1987	Joseph A. Ball Ciprian Foiaş J. William Helton Allen Tannenbaum
+ PDF Chat	Nonlinear solutions of Nevanlinna-Pick interpolation problems.	1987	Joseph A. Ball J. William Helton Changhyun Sung
+	Classical Control Using H-infinity Methods: An Introduction to Design	1987	J. William Helton Orlando Merino
+ PDF Chat	The spectrum of a matrix with respect to an algebra	1987	J. William Helton
+ PDF Chat	Applications to factorization, interpolation, and approximation	1987	J. William Helton
+	Representing shift invariant subspaces	1987	J. William Helton
+	Optimization, matrix inequalities, and matrix completions	1987	J. William Helton
+ PDF Chat	Fractional maps and Grassmannians	1987	J. William Helton
+ PDF Chat	Operator Theory, Analytic Functions, Matrices, and Electrical Engineering	1987	J. William Helton
+	Beurling-Lax representations using classical Lie groups with many applications. IV. GL(n, R), U∗(2n), SL(n,C), and a solvable group	1986	Joseph A. Ball J. William Helton
+	Robust Stabilization of a Family of Plants with Varying Number of Right Half Plane Poles	1986	M.S. Verma J. William Helton Edmond Jonckheere
+	A Bang-Bang theorem for optimization over spaces of analytic functions	1986	J. William Helton Roger Howe
+	Interpolation problems of Pick-Nevanlinna and Loewner types for meromorphic matrix functions: Parametrization of the set of all solutions	1986	Joseph A. Ball J. William Helton
+	Beurling-Lax Representations Using Classical Lie Groups with Many Applications III: Groups Preserving Two Bilinear Forms	1986	Joseph A. Ball J. William Helton
+	Worst case analysis in the frequency domain: The H&lt;sup&gt;∞&lt;/sup&gt;approach to control	1985	J. William Helton
+	Signature preserving linear maps of Hermitian matrices	1985	J. William Helton Leiba Rodman
+	H&lt;sup&gt;∞&lt;/sup&gt;-optimal feedback controllers for linear multivariable systems	1984	Brian Francis J. William Helton G. Zames
+	Beurling-Lax representations using classical Lie groups with many applications II: GL(n,�) and Wiener-Hopf factorization	1984	Joseph A. Ball J. William Helton
+	Power spectrum reduction by optimal Hankel norm approximation of the phase of the outer spectral factor	1984	Edmond Jonckheere J. William Helton
+	Applications of Pick-Nevanlinna interpolation theory to retention-solubility studies in the lungs	1983	John Evans J. William Helton
+	Factorization results related to shifts in an indefinite metric	1982	Joseph A. Ball J. William Helton
+ PDF Chat	Non-Euclidean functional analysis and electronics	1982	J. William Helton
+	Subinvariants for Analytic Mappings on Matrix Balls	1981	Joseph A. Ball J. William Helton
+	The distance of a function to H∞ in the Poincaré metric; electrical power transfer	1980	J. William Helton
+	Nonnormal dilations, disconjugacy and constrained spectral factorization	1980	Joseph A. Ball J. William Helton
+	Comments on "Systems with infinite-dimensional state space: The Hilbert space approach"	1976	James A. Dyer J. William Helton
+	The first variation of the scattering matrix	1976	J. William Helton James Ralston
+	A Spectral Factorization Approach to the Distributed Stable Regular Problem; the Algebraic Riccati Equation	1976	J. William Helton
+	Systems with infinite-dimensional state space: The Hilbert space approach	1976	J. William Helton
+ PDF Chat	Book Review: Indefinite inner product spaces	1975	J. William Helton
+ PDF Chat	Traces of commutators of integral operators	1975	J. William Helton Roger Howe
+	Discrete time systems, operator models, and scattering theory	1974	J. William Helton
+ PDF Chat	Continuity of Linear Fractional Transformations on an Operator Algebra	1973	J. William Helton
+	Integral operators: Traces, index, and homology	1973	J. William Helton Roger Howe
+ PDF Chat	Continuity of linear fractional transformations on an operator algebra	1973	J. William Helton
+	The Cascade Loading of Passive Hilbert Ports	1972	J. William Helton A. H. Zemanian
+	Passive network realization using abstract operator theory	1972	J. William Helton
+ PDF Chat	Infinite Dimensional Jordan Operators and Sturm-Liouville Conjugate Point Theory	1972	J. William Helton
+ PDF Chat	Infinite dimensional Jordan operators and Sturm-Liouville conjugate point theory	1972	J. William Helton
+ PDF Chat	Jordan operators in infinite dimensions and Sturm Liouville conjugate point theory	1972	J. William Helton
+	Unitary operators on a space with an indefinite inner product	1970	J. William Helton
+	Invariant subspaces of certain commuting families of operators on linear spaces with an indefinite inner product	1968	J. William Helton

Common Coauthors

Coauthor	Papers Together
Scott McCullough	56
Igor Klep	40
Joseph A. Ball	29
Orlando Merino	20
Harry Dym	17
Jiawang Nie	15
Eric Evert	11
Leiba Rodman	10
Victor Vinnikov	10
Mihai Putinar	9
Adam Bene Watts	8
Trent E. Walker	7
Jurij Volčič	6
Ilya M. Spitkovsky	6
Robert E. Skelton	5
Roland Speicher	5
Mark Stankus	5
Juan F. Camino	5
Vladimir Bolotnikov	5
Aidan Epperly	4
Maurı́cio C. de Oliveira	4
Markus Schweighofer	4
Jeremy M. Greene	4
Christopher Nelson	4
Jeremy S. Semko	3
Meric Augat	3
Shiyuan Huang	3
Ciprian Foiaş	3
Ryan Tully‐Doyle	3
F. Dell Kronewitter	3
Hugo J. Woerdeman	3
Tobias Mai	3
Roger Howe	3
M. A. Kaashoek	2
Seyed Sajjad Nezhadi	2
Kenneth R. Davidson	2
Ruth Williams	2
Joshua A. Hernandez	2
Daniel P. McAllaster	2
Jonathan Arazy	2
Vern I. Paulsen	2
Jean–Bernard Lasserre	2
Aharon Atzmon	2
Anirban Chowdhury	2
J. E. Pascoe	2
L. A. Coburn	2
Yi Fu	2
Edmond Jonckheere	2
Damon M. Hay	2
David F. Schwartz	2

Commonly Cited References

Action	Title	Year	Authors	# of times referenced
+ PDF Chat	Linear matrix inequality representation of sets	2006	J. William Helton Victor Vinnikov	31
+ PDF Chat	The matricial relaxation of a linear matrix inequality	2012	J. William Helton Igor Klep Scott McCullough	26
+	Completely Bounded Maps and Operator Algebras	2003	Vern I. Paulsen	24
+	Convex Noncommutative Polynomials Have Degree Two or Less	2004	J. William Helton Scott McCullough	23
+	A positivstellensatz for non-commutative polynomials	2004	J. William Helton Scott McCullough	23
+	Matrix Inequalities: A Symbolic Procedure to Determine Convexity Automatically	2003	Juan F. Camino J. William Helton Robert E. Skelton Jieping Ye	23
+	Matrix Convexity: Operator Analogues of the Bipolar and Hahn–Banach Theorems	1997	Edward G. Effros Søren Winkler	23
+	Real algebraic geometry	2014	Jacek Bochnak Michel Coste Marie-Françoise Roy	22
+	Every free basic convex semi-algebraic set has an LMI representation	2009	J. William Helton Scott McCullough	22
+	Noncommutative convexity arises from linear matrix inequalities	2006	J. William Helton Scott McCullough Victor Vinnikov	21
+ PDF Chat	Foundations of Free Noncommutative Function Theory	2014	Dmitry S. Kaliuzhnyi-Verbovetskyi Victor Vinnikov	21
+	Harmonic Analysis of Operators on Hilbert Space	1970	Béla Szõkefalvi-Nagy Ciprian Foiaş Hari Bercovici László Kérchy	21
+ PDF Chat	Free analysis questions II: The Grassmannian completion and the series expansions at the origin	2010	Dan-Virgil Voiculescu	19
+	Interior-Point Polynomial Algorithms in Convex Programming	1994	Yurii Nesterov Arkadi Nemirovski	18
+	None	2003	Dan Voiculescu	18
+ PDF Chat	Every convex free basic semi-algebraic set has an LMI representation	2012	J. William Helton Scott McCullough	17
+	The convex Positivstellensatz in a free algebra	2012	J. William Helton Igor Klep Scott McCullough	16
+	"Positive" Noncommutative Polynomials Are Sums of Squares	2002	J. William Helton	16
+	Real Algebraic Geometry	1998	Frédéric Mangolte Jean-Philippe Rolin Kurdyka Krzysztof Saugata Basu Victoria Powers	16
+	A unified algebraic approach to linear control design	2003	Takao Watanabe	16
+ PDF Chat	Operator Theory, Analytic Functions, Matrices, and Electrical Engineering	1987	J. William Helton	16
+	Singularities of rational functions and minimal factorizations: The noncommutative and the commutative setting	2008	Dmitry S. Kaliuzhnyi-Verbovetskyi Victor Vinnikov	15
+	Engineering Systems and Free Semi-Algebraic Geometry	2008	Maurı́cio C. de Oliveira J. William Helton Scott McCullough Mihai Putinar	15
+	Advances in convex optimization: conic programming	2006	Arkadi Nemirovski	15
+	Structured semidefinite programs and semialgebraic geometry methods in robustness and optimization	2000	Pablo A. Parrilo	14
+	Global Optimization with Polynomials and the Problem of Moments	2001	Jean B. Lasserre	14
+ PDF Chat	The Lax conjecture is true	2005	Adrian S. Lewis Pablo A. Parrilo M. V. Ramana	13
+	Factorization of operator-valued polynomials in several non-commuting variables	2001	Scott McCullough	13
+	Convex Matrix Inequalities Versus Linear Matrix Inequalities	2009	J. William Helton Scott McCullough Mihai Putinar Victor Vinnikov	13
+ PDF Chat	Subalgebras of C*-algebras	1969	William Arveson	13
+ PDF Chat	Global Holomorphic Functions in Several Noncommuting Variables	2014	Jim Agler John E. McCarthy	12
+	The noncommutative Choquet boundary	2007	William Arveson	12
+	Semidefinite Optimization and Convex Algebraic Geometry	2012	Grigoriy Blekherman Pablo A. Parrilo Rekha R. Thomas	12
+ PDF Chat	The Krein-Milman theorem in operator convexity	1999	Corran Webster Søren Winkler	11
+	Free holomorphic automorphisms of the unit ball of B(ℋ) n	2009	Gelu Popescu	11
+ PDF Chat	Handbook of Semidefinite Programming	2000	Henry Wolkowicz Romesh Saigal Lieven Vandenberghe	11
+	Free holomorphic automorphisms of the unit ball of $B(H)^n$	2008	Gelu Popescu	10
+	Worst case analysis in the frequency domain: The H&lt;sup&gt;∞&lt;/sup&gt;approach to control	1985	J. William Helton	10
+ PDF Chat	On Tractable Approximations of Uncertain Linear Matrix Inequalities Affected by Interval Uncertainty	2002	Aharon Ben‐Tal Arkadi Nemirovski	10
+	Strong majorization in a free ✱-algebra	2006	J. William Helton Scott McCullough Mihai Putinar	10
+ PDF Chat	A Nichtnegativstellensatz for polynomials in noncommuting variables	2007	Igor Klep Markus Schweighofer	9
+	Operator Positivstellensätze for noncommutative polynomials positive on matrix convex sets	2016	Aljaž Zalar	9
+	Free holomorphic functions on the unit ball of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mi>B</mml:mi><mml:msup><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mi mathvariant="script">H</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mi>n</mml:mi></mml:msup></mml:math>, II	2009	Gelu Popescu	9
+	Moments, Positive Polynomials and Their Applications	2009	Jean B. Lasserre	9
+	Irreducible noncommutative defining polynomials for convex sets have degree 4 or less	2007	Harry Dym J. William Helton Scott McCullough	9
+	Proper analytic free maps	2010	J. William Helton Igor Klep Scott McCullough	9
+ PDF Chat	Sufficient and Necessary Conditions for Semidefinite Representability of Convex Hulls and Sets	2009	J. William Helton Jiawang Nie	9
+	Semidefinite Programming	1996	Lieven Vandenberghe Stephen Boyd	9
+	Primal-Dual Interior-Point Methods for Semidefinite Programming: Convergence Rates, Stability and Numerical Results	1998	Farid Alizadeh Jean-Pierre A. Haeberly Michael L. Overton	9
+ PDF Chat	Subalgebras of C*-algebras II	1972	William Arveson	9