Ralitza KovachevaScientific Publications

  1. "A Criterion for the m-Meromorphy of Functions", in Russian, International Conference on Constrictive Theory of Functions - Blagoevgrad, 1977; Proceedings; Publ. House of the Bulgarian Academy of Sciences; pp. 81-95.
  2. "On Rational Approximation of Meromorphic Functions", Dokl. Soviet Acad. Nauk, in Russian, 1978; 241; 3; pp.540-544
  3. "On Rational Approximation of Meromorphic Functions", English Translation Dokl. Soviet Acad. Nauk, vol. 19 (1978), No 4
  4. Ph. D. Dissertation, in Russian, 1978; MIAN Institute Steklov, Preprint of MIAN.
  5. "Generalized Pade Approximants and Meromorphic Continuation of Functions", Matem. Sbornik, in Russian, 1979; 109; 151; pp. 365-377
  6. "Generalized Pade Approximants and Meromorphic Continuation of Functions", English Translation Math. USSR, Sbornik, vol. 37 (1980), no. 3
  7. "Convergence of Generalized Pade Approximants"; Internationale Konferenz fuer komplexe Analysis und Differentialgleichungen - 1980, Proceedings in "Kongress - und Tagungsberichte der Martin-Luther-Universitaet Halle Wittenberg";1980; WB 14/1980; pp. 51-54.
  8. "On the Best Rational Approximation in L2 on a Circle", in Russian, 1981; Pliska, 4; pp. 15-21
  9. Uniform Convergence of Pade Approximants, Diagonal Case"; International Conference on Complex Analysis and Applications, Varna, 1981,Proceedings, pp.285-292
  10. "On the Convergence of Generalized Pade Approximants", in Russian, Serdica; 1982; 8; 82- 90.
  11. "Convergence of Interpolating Rational Functions for Some Classes of Holomorphic Functions"; International Conference on Constructive Function Theory, Varna,1981, Proceedings, 1982; pp.382-385.
  12. "The Zeros of Unity and Meromorphic Continuation of Functions"; Lecture Notes of Mathematics; 1983;1039; pp. 264-276
  13. "Uniform Convergence of Pade Approximants, General Case"; Serdica; 1984; 10; pp. 19-28.
  14. "Zerlegung der holomorphen Funktionen in Interpolationsreihen nach den Einheitswurzeln"; in German, Comptes Rendus de l'Academie bulgare des Sciences; 1984; 37; 4; pp. 441-444; R. K. Kowatscheva.
  15. "Something Else about the Meromorphic Continuation of Functions"; International Conference of Constructive Theory of Functions, Varna, 1984, Proceedings, 1984; pp. 479-487.
  16. "Pade Approximants and Inverse Problems"; ICNO, Varna, 1984, Proceedings; 1984; pp. 650-654.
  17. "Chebyshev Rational Approximants"; International Conference on Complex Analysis and Applications, Varna, 1985, Proceedings. 1986; pp.378- 387.
  18. "Best Chebyshev Approximants and Poles of Functions"; Comptes Rendus de l'Academie bulgare des Sciences; 1986; 39; 12; pp.27- 31.
  19. Best Chebyshev Approximants and Spherical Convergence"; Lecture Notes of Mathematics; 1986; 1237; pp.69-75
  20. "Diagonal Pade Approximants, Chebyshev Rational Approximants and Poles of Functions"; "Nonlinear Numerical Methods and Rational Approximation", D. Reidel Publishing Co.;1988; pp.93-103.
  21. "The Density of the Alternation Points of Chebyshev Rational Approximants to a Real-valued Continuous Functions"; Comptes Rendus de l'Academie Bulgare des Sciences; 1988; 42; 8; pp.33- 36.
  22. Die Einheitswurzeln und die Zerlegung der Funktionen in Interpolationsreihen"; in German, Pliska; 1989; 10; pp. 3 - 11, R. K. Kowatschewa.
  23. "Generalized Pade Approximants of Kakehashi's Type and Meromorphic Continuation of Functions"; "Deformations of Math. Structures", Selected Papers, Kluwer Acad. Publ. ;1989; pp.151- 159. .
  24. On the behavior of Chebyshev rational approximants with fixed number of poles"; Comptes Rendus de l’ Academie Bulgare des Sciences; 1989; 42; 2; pp.41-44.
  25. "The Behavior of Chebyshev Rational Approximants with a Fixed Number of the Free Poles"; Matematica Balkanika; 1989; 3; 3/4;pp. 244-256.
  26. "Diagonal Rational Chebyshev Approximants and Holomorphic Continuation of Functions"; Analysis; 1990; 10; pp.147-161.
  27. "On the Diagonal Rational Chebyshev Approximants and the Continuations of Functions"; Comptes Rendus de l'Academie Bulgare des Sciences; 1990;43; 4; pp.35 -38.
  28. "Regions of Uniform Convergence of Chebyshev Approximants with an Unbounded Number of the Free Poles "; Topics in Polynomials of One and Several Variables and Their Applications, Selected Papers, World Scientific Publ. Co.; 1991; pp.26-38.
  29. "Quasiregular Extension and Approximation of Dualities Generated by the Generalized Hurwitz Problem"; in "Geometric Function Theory", selected papers, Pitman Research Notes in Mathematics Series; 1991; pp.100-118; with J, Lawrynowicz .
  30. “On the convergence of Rational Functions of Best Uniform Approximation with unbounded number of poles”; with I. V. Ivanov and J. Gilewicz, Comptes Rendus de l'Academie bulgare des Sciences; 45. No.11, 1992; pp. 23-26.
  31. “Rational Functions of best Uniform Approximation - Open Problems”; Proceedings of International Conference "Open Problems in Approximation Theory"; Vonesta Voda, Bulgaria, 1993; 21 - 25.
  32. “On the Zeros of Pade Approximants and Pade Error Functions for Special Class of Functions”; Proceedings of International Conference on Numerical Methods and Rational Approximation; Antwerpen, 1993; Kluwer Verlag; 1993; 229 - 237.
  33. “Zeros of Pade Approximants for Entire Functions with Smooth Maclaurean Coefficients”; with E. B. Saff, Journal of Approx.Theory; 1994; 79; 347 - 384.
  34. “The Second Order Modulus Revisited”; with H. H. Gonska, Conf. Sem. Mat. Univ. Bari; 1994; 1 - 36.
  35. “On the Zeros of Pade Approximants”; Proceedings of Banach Semester in Complex Analysis -1994; Polish Academy of Sciences 1996.
  36. “Zeros of Pade Error Functions for Functions with Smooth Maclaurin Coefficients”, Journal of Approximation Theory; 1995; 83; 371 - 391.
  37. “A Note on the Limiting Distribution of the Zeros of Pade Approximants”; Journal Comp. Math. Application; 1995; 30; 147 - 153.
  38. “Rational Functions of best Uniform Approximation and Holomorphic Continuation of Functions”; with I.V.Ivanov and J. Gilewicz; Journal of Approximation and Applications; 1996, vol.12, 1, 1 -10.
  39. “Rational Geometric Approximation on [0,8)”, with H. P. Blatt; East Journal of Approximations; 1996; Vol. 2; 1, 31 - 40.
  40. “An Extension of Montel's Theorem to Some Approximating Sequences”; with H. H. Gonska; Bulletin de la Societe des Sciences et de Lettres de Lodz, Vol. XLV1, 1997, pp. 73 - 86
  41. “An analogue of Montel's theorem to rational approximating sequences”; Comptes Rendus de l'Academie bulgare des Sciences; tome 50, N. 3, 1997, pp 9 - 12
  42. “Approximation on Unbounded Intervals”, with H.P.Blatt and V. Andrievski, Analysis 17, 1997, 197 - 218.
  43. “On the convergence of rational functions of best Lp– approximation”, Results of Mathematics, 36(1999), 281 - 290.
  44. “On sign changes in polynomial L1-approximation”, with H. –P. Blatt, Approximation theory and its applications, Kiev, 1999, Proceedings, 49 – 55. Institute Mat. Nats. Akad. Nauk Ukr. Mat. Zastos. I Akad. Nauk Ukraini, Inst. Mat. Kiev, 2000,
  45. “Approximation on Unbounded Intervals”, with H.P.Blatt and V. Andrievski, Analysis 17, 1997, 197 - 218.
  46. “An Analogue of Montel’s Theorem to rational functions of best Lp –approximation”, with J. Lawrynowicz, Journal of Approximation Theory 115, 2002, no. 1, 56 - 71.
  47. “On sign changes in weighted polynomial L1 approximation”, with H.-P. Blatt, R. Grothmann, Acta Mathematica Hungarica, 95(4), 2002, pp. 309 – 322.
  48. “An Analogue of Montel’s Theorem for some classes of rational functions”, with J. Lawrynowicz, Chechoslovak Mathematics J. 52(127), 2002, no 3., 483 – 498.
  49. On the distribution of alternation points in uniform rational approximation, with H.-P. Blatt and R. Grothmann, Comptes rendus de l’Academie bulgare des Sciences 55, 8, 2002, pp. 5 – 10. Ibid; Volume dedicated to Prof. Malik, University of New Delhi, India, 2007
  50. “Alternation points in rational Chebyshev approximation”, with H.-P. Blatt and R. Grothmann, Constructive Theory of Functions, Varna 2002, Proceedings, pp. 213 – 219.
  51. “Discrepancy estimates in rational Chebyshev approximation”, with H.-P. Blatt and R. Grothmann, Constructive Theory of Functions, Varna 2002, Proceedings, pp. 220 – 225.
  52. “Critical dimension 13 in approximation related to fractals of algebraic structure.” XIII conference of Anal. Functions, with J. Lawrynowicz, Bull. Soc. Sci. Lett. Lodz, Rech. Deform. 379(2002) 77 – 102.
  53. "Rational functions of best Lp - approximation and and analytic continuability", with J Lawrynowicz, Results of Mathematics 43, 2003, no. 1-2, pp. 156 – 162.
  54. Dissertation for Doctor of Mathematical Sciences (Dr Sci mat.), 2003, Sofia, Preprint of Bulgarian Academy of Sciences.
  55. “Poles and alternation points in rational Chebyshev approximation ”, with H.-P. Blatt and R. Grothmann; CMFT (Constructive Methods of Functional Theory) 3, 2004, 165 - 177; Special Volume dedicated to Prof. Gaier.
  56. “Sequences with equi-distributed extreme points in uniform polynomial approximation”, with H.-P. Blatt and R. Grothmann, Journal of Approximation Theory, 126, 2004, 157 – 140.
  57. “Uniform convergence of best Chebyshev rational approximants to a real-valued function on [-1,1]”, Banach Center Publications, 2004.
  58. “Domains of uniform convergence of real Chebyshev rational approximants”, Analysis 25(2005), 159-169.
  59. “ Zeros of partial sums and overconvergence”, Serdica Math. J. 2008, 34, pp. 467-482.
  60. “Sign changes in rational L(1) approximation”, Ukranian Mat. Zh. 58(2006), no 2, 283-287, Translation in English: Ukranian Math. Journal, 58(2006), no2, 318-323.
  61. “Ostrowski gaps, zeros and overconvergence”, Bulletin de la Societe des Sciences et de Lettres de Lodz, Vol. XLV1, 2006, Vol.L,pp.53-70.
  62. “Ostrowski gaps, zeros and overconvergence, II”, Comptes Rendus de l'Academie bulgare des Sciences, TOME 60, No.6, 2007.
  63. “Overconvergence and zero distribution of Fourier series”, Comptes Rendus de l'Academie bulgare des Sciences, TOME 61, No.11, 2008.
  64. “On uniform convergence of rational functions of best Chebyshev approximation to a real valued function on [-1,1]. Applied Complex and Quaternionic Appoximation, Edizione Nuova Cultura, ed, R. Kovacheva, J.Lawryniwicz, St. Machiafava, 2007.
  65. “Riemann surface modelling of orbit systems for integral trajectories of a body sliding on the surface", with J. Lawrynowicz, W. Leszek, Bull. Soc. Sci. Lett. Lodz,vol.LVII,101-112, 2007
  66. “Normal families of meromorphic functions”, C.R.Acad. Bulg. 2010, tome 63, No 6, 807-814.
  67. “Growth behavior and zero distribution of rational functions”, with H.P.Blatt, Constructive Approximation, accepted 2010, 34 (3) (2011),393-420.
  68. “Growth behavior and zero distribution of maximally convergent rational approximants” with HP Blatt, R.Grothmann, Proceedings of 13th International Conference in Approximation Theory, San Antonio, Texas, 2010, Springer Verlag 2011
  69. “Regions of meromorphy and value distribution of geometrically converging rational approximants”, with H.P.Blatt, R, Grothmann, Journal of Mathematical Analysis and Applications, 382 (2011), 66-76, 2011.
  70. “On the distribution of zeros and poles of rational approximants on intervals: with Vl. Andrieyevskij, HP Blatt, Abstract Analysis and Applications, vol. 2012, (2012). Article ID 961209, 21 pages, 2012. doi:10.1155/2012/961209
  71. "Montel's type results and zero distribution of sequences of rational functions", Bullettin de la Societe et des letters de Lo?dz?, Issue dedicated to the memory of Prof. Ingarden, vol XXIV,101-112, 2012, 101-115
  72. “Rational Chebyshev approximants - the real case,survey, Bullettin de la Societe et des letters de Lodz, Issue dedicated to the memory of Prof. Tamrazov, vol. XXVII, 2012, pp. 70-95.
  73. “Maximally convergent series of multipoint Pade approximants and distribution of interpolation points", AIP Conf. Proc. 1570, pp. 401-409, 2013
  74. "Distribution of zeros of the Hermite-Padé polynomials for a system of three functions, and the Nuttall condenser", with S.P. Suetin, Proceedings of the Steklov Institute of Mathematics, 284 (1), pp. 168-191
  75. "Distribution of interpolation points of maximally convergent multipoint Pade approximants", with H. P. Blatt, J. of Approximation Theory, Vol. 191, 2014, pp. 46 - 57.
  76. "Distribution of Points of Interpolation and of Zeros of Exactly Maximally Convergent Multipoint Padé Approximants " Applied mathematics 2015, 6, 737 -744.
  77. "Distribution of points of interpolation of multipoint Pade approximants; the nonequilibrium case"Vol XLIV, No.3, pp. 11 - 20. Bulletin de la Societe des Sciences et de Lettres de Lodz, Vol. XLIV, 2014, no. 3,pp.53-70. .