Publications in Refereed Journals

  1. J.A. Ball, Factorization and invariant subspaces for noncontractions, Bull. Amer. Math. Soc. 80 (1974), 896-900.
  2. J.A. Ball, Models for noncontractions, J. Math. Anal. Appl. 52 (1975), 235-254.
  3. J.A. Ball, Hardy space expectation operators and reducing subspaces, Proc. Amer. Math. Soc. 47 (1975), 351-357.
  4. J.A. Ball, A norm estimate for an integral operator, Transport Theory and Statistical Physics 4 (1975), 67-69.
  5. J.A. Ball and A. Lubin, On a class of contractive perturbations of restricted shifts, Pacific J. Math. 63 (1975), 309-332.
  6. J.A. Ball and W. Greenberg, A Pontrjagin space analysis of the supercritical transport equation, Transport Theory and Statistical Physics 4 (1975), 143-154.
  7. M.B. Abrahamse and J.A. Ball, Analytic Toeplitz operators with automorphic symbol II, Proc. Amer. Math. Soc. 59 (1976), 323-328.
  8. J.A. Ball, Rota's theorem for general functional Hilbert space, Proc. Amer. Math. Soc. 65 (1977), 55-61.
  9. J.A. Ball, Factorization and model theory for contraction operators with unitary part, Memoirs of the American Mathematical Society No. 198, (1978), 68 pages.
  10. J.A. Ball, R.F. Olin and J.E. Thomson, Weakly closed algebras of subnormal operators, Illinois J. Math. 22 (1978), 315-326.
  11. J.A. Ball, Operators of class $C_{00}$ over multiply connected domains, Mich. Math. J. 25 (1978), 183-196.
  12. J.A. Ball, A lifting theorem for operator models of finite rank on multiply connected domains, J. Operator Theory 1 (1979), 3-25.
  13. J.A. Ball, Operator extremal problems, expectation operators and applications to operators on multiply connected domains, J. Operator Theory 1 (1979), 153-175.
  14. J.A. Ball, Interpolation problems and Toeplitz operators on multiply connected domains, Integral Equations and Operator Theory 4 (1981), 172-184.
  15. J.A. Ball and J.W. Helton, Nonnormal dilations, disconjugacy and constrained spectral factorization, Integral Equations and Operator Theory 3 (1980), 215-309.
  16. J.A. Ball and J.W. Helton, Subinvariants for analytic mappings on matrix balls, Analysis 1 (1981), 217-226.
  17. J.A. Ball and J.W. Helton, Lie groups over the field of rational functions, signed spectral factorization, signed interpolation and amplifier design, J. Operator Theory 8 (1982), 19-64.
  18. J.A. Ball and J.W. Helton, Factorization results related to shifts in an indefinite metric, Integral Equations and Operator Theory 5 (1982), 632-658.
  19. J.W. Helton and J.A. Ball, The cascade decompositions of a given system vs. the linear fractional decompositions of its transfer function, Integral Equations and Operator Theory 5 (1982), 341-385.
  20. J.A. Ball and J.W. Helton, A Beurling-Lax theorem for the Lie group $U(m,n)$ which contains most classical interpolation, J. Operator Theory 9 (1983), 107-142.
  21. J.A. Ball, Interpolation problems of Nevanlinna-Pick and Loewner types for meromorphic matrix functions, Integral Equations and Operator Theory 6 (1983), 804-840.
  22. J.A. Ball and J.W. Helton, Beurling-Lax representations using classical Lie groups with many applications II: $GL(n, \bold C)$ and Wiener-Hopf factorization, Integral Equations and Operator Theory 7 (1984), 291-309.
  23. J.A. Ball and J.W. Helton, Beurling-Lax representations using classical Lie groups with many applications III: groups preserving forms, Amer. J. Math. 108 (1986), 95-174.
  24. J.A. Ball and I. Gohberg, Shift invariant subspaces, factorization and interpolation for matrices I: the canonical case, Lin. Alg. Appl. 74 (1986), 87-150.
  25. J.A. Ball and I. Gohberg, A commutant lifting theorem for triangular matrices with diverse applications, Integral Equations and Operator Theory 8 (1985), 205-267.
  26. J.A. Ball and J.W. Helton, Interpolation problems of Pick-Nevanlinna and Loewner types for meromorphic matrix functions: parametrization of the set of all solutions, Integral Equations and Operator Theory 9 (1986), 155-203.
  27. J.A. Ball and J.W. Helton, Beurling-Lax representations using classical Lie groups with many applications IV: $GL(n, \bold R)$, $U^*(2n)$, $SL(n,\bold C)$ and a solvable group, J. Functional Analysis 69 (1986), 178-206.
  28. J.A. Ball and I. Gohberg, Pairs of shift invariant subspaces of matrices and noncanonical factorization, Linear and Multilinear Algebra 20 (1986), 27-61.
  29. J.A. Ball and A.C.M. Ran, Optimal Hankel norm model reductions and Wiener-Hopf factorization I: The canonical case, SIAM J. Control & Optimization 25 (1987) 362-382.
  30. J.A. Ball and T.L. Kriete, Operator-valued Nevanlinna-Pick kernels and the functional models for contraction operators, Integral Equations and Operator Theory 10 (1987), 17-61.
  31. J.A. Ball and A.C.M. Ran, Global inverse spectral problems for rational matrix functions, Lin. Alg. Appl. 86 (1987), 237-282.
  32. J.A. Ball and A.C.M. Ran, Local inverse spectral problems for rational matrix functions, Integral Equations and Operator Theory 10 (1987), 349-415.
  33. J.A. Ball, I. Gohberg and L. Rodman, Minimal factorization of meromorphic matrix functions in terms of local data, Integral Equations and Operator Theory 10 (1987), 309-348.
  34. J.A. Ball and N. Cohen, Sensitivity minimization in $H^\infty$ norm: parametrization of all suboptimal solutions, Int. J. Control 46 (1987), 785-816.
  35. J.A. Ball and A.C.M. Ran, Optimal Hankel norm model reduction and Wiener-Hopf factorization II: the noncanonical case, Integral Equations and Operator Theory 10 (1987), 416-436.
  36. J.A. Ball and A.C.M. Ran, Hankel norm approximation of real symmetric rational matrix functions, Systems \& Control Letters 9 (1987), 105-116.
  37. J.A. Ball, J.W. Helton and C.H. Sung, Nonlinear solutions of Nevanlinna-Pick interpolation problems, Michigan Math. J. 34 (1987), 375-389.
  38. J.A. Ball, C. Foias, J.W. Helton and A. Tannenbaum, On a local nonlinear commutant lifting theorem, Indiana Univ. Math. J. 36 (1987), 693-709.
  39. J.A. Ball and J.W. Helton, Shift invariant manifolds and nonlinear analytic function theory, Integral Equations and Operator Theory 11 (1988), 615-725.
  40. J.A. Ball, C. Foias, J.W. Helton and A. Tannenbaum, A Poincare-Dulac approach to a nonlinear Beurling-Lax-Halmos theorem, J. Math. Anal. Appl. 139 (1989), 496-514.
  41. D.W. Luse and J.A. Ball, Frequency-scale decomposition of $H^{\infty}$ disk problems, SIAM J. Control \& Opt. 27 (1989), 814-835.
  42. J.A. Ball and J.W. Helton, Interconnection of nonlinear causal systems, {IEEE Trans. Aut. Control 34 (1989), 1132-1140.
  43. J.A. Ball and M. Rakowski, Minimal McMillan degree rational matrix functions with prescribed local zero-pole structure,Linear Alg. Appl. 137/138 (1990), 325-349.
  44. J.A. Ball and J. Kang, Matrix polynomial solutions of tangential Lagrange-Sylvester interpolation conditions of low McMillan degree, Linear Alg. Appl.}137/138 (1990), 699-746.
  45. J.A. Ball, I. Gohberg and L. Rodman, Common minimal multiples and divisors for rational matrix functions, Linear Alg. Appl. 137/138 (1990), 621-662.
  46. A.C. Antoulas, J.A. Ball, J. Kang and J.C. Willems, On the solution of the minimal rational interpolation problem,Linear Alg. Appl. 137/138 (1990), 511-573.
  47. J.A. Ball, I. Gohberg, L. Rodman and T. Shalom, On the eigenvalues of matrices with given upper triangular part, Integral Equations and Operator Theory 13 (1990), 488-497.
  48. J. A. Ball and K.F. Clancey, An elementary description of partial indices of rational matrix functions, Integral Equations and Operator Theory 13 (1990), 316-322.
  49. J.A. Ball, I. Gohberg and L. Rodman, Simultaneous residue interpolation for rational matrix functions, Integral Equations and Operator Theory 13 (1990), 611-637.
  50. J.A. Ball, N. Cohen and L. Rodman, Zero data and interpolation problems for rectangular matrix polynomials, Linear and Multilinear Alg. 29 (1991), 53-78.
  51. J.A. Ball and B. Taub, Factoring spectral matrices in linear quadratic models, Economics Letters 35 (1991), 39-44.
  52. J.A. Ball, I. Gohberg and L. Rodman, Boundary Nevanlinna-Pick interpolation for rational matrix functions, J. Math. Systems, Estimation, and Control 1 (1991), 131-164.
  53. J.A. Ball and M. Rakowski, Null-pole subspaces of nonregular rational matrix functions, Linear Alg. Appl. 159 (1991), 81-120.
  54. J.A. Ball and J.W. Helton, Inner-outer factorization of nonlinear operators, J. Functional Analysis 104 (1992), 363-413.
  55. J.A. Ball and T. Fanney, Uniform limits of sequences of polynomials and their derivative, Proc. Amer. Math. Soc. 114 (1992), 363-413.
  56. J.A. Ball and J.W. Helton, Nonlinear $H^{\infty}$ theory for stable plants, Mathematics of Control, Signals and Systems} 5 (1992) 233-261.
  57. J.A. Ball, J.W. Helton and M. Verma, A factorization principle for stabilization of linear control systems, Int. J. of Robust and Nonlinear Control 1 (1991), 229-294.
  58. D. Alpay, J.A. Ball, I. Gohberg and L. Rodman, State space theory of automorphisms of rational matrix functions, Integral Equations and Operator Theory 15 (1992), 349-377.
  59. J.A. Ball, I. Gohberg and L. Rodman, The structure of flat gain matrices that satisfy two-sided interpolation requirements, Systems \& Control Letters 20 (1993), 401-412.
  60. J.A. Ball, J.W. Helton and M.L. Walker, $H^{\infty}$ control for nonlinear systems with output feedback, IEEE Trans. Auto. Control 38 (1993), 546-559.
  61. J.A. Ball and M. Rakowski, Interpolation by rational matrix functions and stability of feedback systems: the 2-block case, J. Math. Systems, Estimation, and Control 4 (1994), 261-318.
  62. J.A. Ball and T.R. Fanney, Pure subjordan operators and simultaneous approximation by a polynomial and its derivative, J. Operator Theory 32 (1995), 43-78.
  63. J.A. Ball, J. Kim, L. Rodman and M. Verma, Minimal degree coprime factorizations of rational matrix functions, Linear Alg. Appl., 186 (1993), 117-164.
  64. J.A. Ball and K. Clancey, Interpolation with meromorphic matrix functions, Proc. Amer. Math. Soc. 121 (1994), 491-496.
  65. J.A. Ball and J. Kim, Stability and McMillan degree for rational matrix interpolants, Lin. Alg. Appl. 196 (1994), 207-232.
  66. J.A. Ball and M. Verma, Factorization and feedback stabilization for nonlinear systems, Systems \& Control Letters, 23 (1994), 187-196.
  67. J.A. Ball, M.A. Kaashoek, G. Groenewald and J. Kim, Column reduced rational matrix functions with given null-pole data in the complex plane, Linear Alg. Appl. 203-204 (1994), 67-110.
  68. J.A. Ball, M. Rakowski and B.F. Wyman, Coupling operators, Wedderburn-Forney spaces, and generalized inverses, Linear Alg. Appl. 203-204 (1994), 111-138.
  69. D. Alpay, J.A. Ball, I. Gohberg and L. Rodman, $J$-unitary preserving automorphisms of rational matrix functions: state space theory, interpolation and factorization, Linear Alg. Appl. 197-198 (1994), 531-566.
  70. D. Alpay, J.A. Ball, I. Gohberg and L. Rodman, The two-sided residue interpolation problem in the Stieltjes class for matrix functions, Linear Alg. Appl. 208-209 (1994), 485-521.
  71. J.A. Ball and J.W. Helton, Summary: Viscosity solutions of Hamilton-Jacobi equations arising in nonlinear $H^\infty$-control problems, J. Math. Systems, Estimation, and Control 6 (1996), 109-112 (full-length version available via anonymous FTP, Retrieval Code: 85105).
  72. J.A. Ball, I. Gohberg and M.A. Kaashoek, Bitangential interpolation for input-output maps of time-varying systems: the continuous time case, Integral Equations and Operator Theory 20 (1994), 1-43.
  73. J.A. Ball, I. Gohberg and M. Rakowski, Reconstruction of a rational nonsquare matrix function from local data, Integral Equations and Operator Theory 20 (1994), 249-305.
  74. J.A. Ball, I. Gohberg and M.A. Kaashoek, Two-sided Nudelman interpolation for input-output operators of discrete time-varying systems, Integral Equations and Operator Theory 21 (1995), 174-211.
  75. J.A. Ball and J. Kim, Bitangential interpolation problems for symmetric rational matrix functions, Linear Alg. Appl. 241-243 (1996), 113-152.
  76. J.A. Ball and A.J. van der Schaft, $J$-inner-outer factorization, $J$-spectral factorization and robust control for nonlinear systems, IEEE Trans. Auto. Control 41 (1996), 379-392.
  77. J.A. Ball and V. Vinnikov, Zero-pole interpolation for matrix meromorphic functions on an algebraic curve with determinantal representation, Acta Applicandae Mathematicae 45 (1996), 239-316.
  78. J.A. Ball and K.F. Clancey, Reproducing kernels for Hardy spaces on multiply connected domains, Integral Equations and Operator Theory, 25 (1996), 35-57.
  79. J.A. Ball, Commutant lifting and interpolation: The time-varying case, Integral Equations and Operator Theory 25 (1996), 377-405.
  80. J.A. Ball, I. Gohberg and M.A. Kaashoek, A frequency response function for linear, time-varying systems, Math. Control Signals Systems 8 (1995), 334-351.
  81. J.A. Ball, I. Gohberg and M.A. Kaashoek, Nudelman interpolation and the band method, Integral Equations and Operator Theory 27(1997), 253-284.
  82. J.A. Ball and V. Vinnikov, Zero-pole interpolation for meromorphic matrix functions on a compact Riemann surface and a matrix Fay trisecant identity, submitted for publication.
  83. J.A. Ball and T.T. Trent, Unitary colligations, reproducing kernel Hilbert spaces, and Nevanlinna-Pick interpolation in several variables, J. Functional Analysis, to appear.
  84. J.A. Ball, P. Kachroo and A.J. Krener, $H_\infty$ tracking for a class of nonlinear systems, Technical Note, IEEE Trans. Automatic Control, to appear.
  85. J.A. Ball and V. Vinnikov, Zero-pole interpolation for matrix meromorphic functions on a compact Riemann surface and a matrix Fay trisecant identity, American J. Math., 121 (1999), 841-888.
Teaching Research Recent Publications Vitae