Erik Christensen

Erik Christensen

Associate professor emeritus


  1. 2024
  2. Published

    Some points of view on Grothendieck's inequalities

    Christensen, Erik, 2024, In: Linear Algebra and Its Applications. 691, p. 196-215 20 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Published

    Unique matrix factorizations associated to bilinear forms and Schur multipliers

    Christensen, Erik, 2024, In: Linear Algebra and Its Applications. 688, p. 215-231

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. 2023
  5. Published

    Bilinear forms, Schur multipliers, complete boundedness and duality

    Christensen, Erik, 2023, In: Mathematica Scandinavica. 129, 3, p. 543-569

    Research output: Contribution to journalJournal articleResearchpeer-review

  6. Published

    Minimal Stinespring Representations of Operator Valued Multilinear Maps

    Christensen, Erik, 2023, In: Journal of Operator Theory. 89, 2, p. 587-601 15 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  7. 2020
  8. Published

    Decompositions of block schur products

    Christensen, Erik, 2020, In: Journal of Operator Theory. 84, 1, p. 139-152

    Research output: Contribution to journalJournal articleResearchpeer-review

  9. Published

    The block Schur product is a Hadamard product

    Christensen, Erik, 2020, In: Mathematica Scandinavica. 126, 3, p. 603-616

    Research output: Contribution to journalJournal articleResearchpeer-review

  10. 2019
  11. Published

    On the complete boundedness of the Schur block product

    Christensen, Erik, 2019, In: Proceedings of the American Mathematical Society. 147, 2, p. 523-532

    Research output: Contribution to journalJournal articleResearchpeer-review

  12. 2017
  13. Published

    Structural properties of close II1 factors

    Cameron, J., Christensen, Erik, Sinclair, A. M., Smith, R. R., White, S. & Wiggins, A. D., 2017, In: Münster Journal of Mathematics. 10, 1, p. 19-37

    Research output: Contribution to journalJournal articleResearchpeer-review

  14. 2016
  15. Published

    Commutator inequalities via Schur products

    Christensen, Erik, 2016, Operator Algebras and Applications: The Abel Symposium 2015. Carlsen, T. M., Larsen, N. S., Neshveyev, S. & Skau, C. (eds.). Springer, p. 127-143 (Abel Symposia, Vol. 12).

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

  16. Published

    Higher weak derivatives and reflexive algebras of operators

    Christensen, Erik, 2016, Operator Algebras and Their Applications: A Tribute to Richard V. Kadison. Doran, R. S. & Park, E. (eds.). American Mathematical Society, p. 69-83 (Contemporary Mathematics, Vol. 671).

    Research output: Chapter in Book/Report/Conference proceedingBook chapterResearchpeer-review

  17. Published

    On weakly D-differentiable operators

    Christensen, Erik, 2016, In: Expositiones Mathematicae. 34, 1, p. 27–42

    Research output: Contribution to journalJournal articleResearchpeer-review

  18. 2014
  19. Published

    Kadison-Kastler stable factors

    Cameron, J., Christensen, Erik, Sinclair, A. M., Smith, R. R., White, S. A. & Wiggins, A. D., 2014, In: Duke Mathematical Journal. 163, 14, p. 2639-2686 57 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  20. Published

    Von Neumann algebras as complemented subspaces of B(H)

    Christensen, Erik & Wang, L., 2014, In: International Journal of Mathematics. 25, 9 p., 1450107.

    Research output: Contribution to journalJournal articleResearchpeer-review

  21. 2013
  22. Published

    C*-algebras nearly contained in a type I C*-algebra

    Christensen, Erik, Sinclair, A. M., White, S. A. & Smith, R. R., Jan 2013, In: Canadian Journal of Mathematics. 65, p. 52-65 14 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  23. Published

    A Remark on the Similarity and Perturbation Problems

    Cameron, J., Christensen, Erik, Sinclair, A. M., Smith, R. R., White, S. & Wiggins, A. D., 2013, In: Mathematical Reports of the Academy of Science. 35, 2

    Research output: Contribution to journalJournal articleResearchpeer-review

  24. 2012
  25. Published

    Perturbations of nuclear C*-algebras.

    Christensen, Erik, Sinclair, A. M., White, S., Smith, R. R. & Winter, W., 2012, In: Acta Mathematica. 208, p. 93-150 58 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  26. Published

    Spectral triples and the geometry of fractals

    Christensen, Erik, Ivan, C. & Schroe, E., 2012, In: Journal of Noncommutative Geometry. 6, p. 249 - 274 26 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  27. Published

    Type II1 factors satisfying the spatial isomorphism conjecture.

    Cameron, J., Christensen, Erik, Sinclair, A. M., Smith, R. R., White, S. & Wiggins, A. D., 2012, In: Proceedings of the National Academy of Sciences USA (PNAS). 109, 5, p. 20338 - 20343 6 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  28. 2010
  29. Published

    Perturbations of C*-algebraic Invariants

    Christensen, Erik, Sinclair, A. M., Smith, R. R. & White, S., 2010, In: Geometric and Functional Analysis. 20, 2, p. 368 - 397 30 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  30. Published

    The spatial isomorphism problem for close separable nuclear C*-algebras

    Christensen, Erik, Sinclair, A. M., Smith, R. R., White, S. A. & Winter, W., 2010, In: Proceedings of the National Academy of Science of the United States of America. 107, 2, p. 587 - 591 5 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  31. 2009
  32. Published

    Extensions and degeneration of spectral triples

    Christensen, Erik & Ivan, C., 2009, In: Communications in Mathematical Physics. 285, 3, p. 925-955 31 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  33. 2008
  34. Published

    Dirac operators and spectral triples for some fractal sets built on curves

    Christensen, Erik, Ivan, C. & Lapidus, M. L., 2008, In: Advances in Mathematics. 217, 1, p. 42 - 78 37 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  35. 2007
  36. Published

    Sums of two-dimensional spectral triples

    Christensen, Erik & Ivan, C., 2007, In: Mathematica Scandinavica. 100, 1, p. 35-60 26 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  37. 2006
  38. Published

    Spectral triples for AF C*-algebras and metrics on the Cantor set

    Christensen, Erik, 2006, In: Journal of Operator Theory. 56, p. 17-46

    Research output: Contribution to journalJournal articleResearchpeer-review

  39. 2004
  40. Published

    Metrics on group C*-algebras and a non-commutative Arzelà-Ascoli Theorem

    Antonescu, C. & Christensen, Erik, 2004, In: Journal of Functional Analysis. 214, p. 247-259

    Research output: Contribution to journalJournal articleResearchpeer-review

  41. 2003
  42. Published

    Hochschild cohomology of factors with property Gamma

    Christensen, Erik, Sinclair, A. M. & Smith, R. R., 2003, In: Annals of Mathematics. 158, 2, p. 597-621

    Research output: Contribution to journalJournal articleResearchpeer-review

  43. Published

    On some problems studied by R.V. Kadison

    Christensen, Erik, 2003, In: Acta Mathematica Sinica. English series. 19, p. 523-534

    Research output: Contribution to journalJournal articleResearchpeer-review

  44. Published

    Property Gamma factors and the Hochschild cohomology problem

    Christensen, Erik, Pop, F., Sinclair, A. M. & Smith, R. R., 2003, In: Proceedings of the National Academy of Science of the United States of America. 100, p. 3865-3869

    Research output: Contribution to journalJournal articleResearchpeer-review

  45. 2001
  46. Published

    Finite von Neumann algebra factors with property Gamma

    Christensen, Erik, 2001, In: Journal of Functional Analysis. 186, p. 366-380

    Research output: Contribution to journalJournal articleResearchpeer-review

  47. Published

    Konvekse mængder

    Christensen, Erik, 2001, 106 p.

    Research output: Book/ReportBookCommunication

  48. 1998
  49. Published

    On invertibility preserving linear mappings, simultaneous triangularization and Property L.

    Christensen, Erik, 1998, In: Linear Algebra and Its Applications. 301, p. 153-170

    Research output: Contribution to journalJournal articleResearchpeer-review

  50. 1997
  51. Published

    Two generalizations of the Gleason-Kahane-Z̀elazko theorem

    Christensen, Erik, Jan 1997, In: Pacific Journal of Mathematics. 177, 1, p. 27-32 6 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  52. Published

    A cohomological characterization of approximately finite dimension von Neumann algebras

    Christensen, Erik, 1997, Operator Algebras and quantum field theory. Rom: International Press, p. 323-328

    Research output: Chapter in Book/Report/Conference proceedingBook chapterResearch

  53. Published

    On the cohomology groups of cerain finite von Neumann algebras

    Christensen, Erik, Pop, F. & Sinclair, A. M., 1997, In: Mathematische Annalen. 307, p. 71-92

    Research output: Contribution to journalJournal articleResearchpeer-review

  54. 1995
  55. Published

    Module mappings into von Neumann algebras and injectivity

    Christensen, Erik & Sinclair, A. M., 1995, In: Proceedings of the London Mathematical Society. 71, p. 618-640

    Research output: Contribution to journalJournal articleResearchpeer-review

  56. 1994
  57. Published

    On von Neumann Algebras which are complemented Subspaces of B(H)

    Christensen, Erik & Sinclair, A. M., 1994, In: Journal of Functional Analysis. 122, p. 91-102

    Research output: Contribution to journalJournal articleResearchpeer-review

  58. Published

    Universally bounded operators on von Neumann algebras of type II*U1

    Christensen, Erik, 1994, Algebraic Methods in Operator Theory. Boston: Birkhäuser Verlag, p. 195-204

    Research output: Chapter in Book/Report/Conference proceedingBook chapterResearch

  59. 1989
  60. Published

    A survey of completely bounded operators

    Christensen, Erik & Sinclair, A. M., Sep 1989, In: Bulletin of the London Mathematical Society. 21, 5, p. 417-448 32 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  61. Published

    Completely bounded isomorphisms of injective von neumann algebras

    Christensen, Erik & Sinclair, A. M., Jun 1989, In: Proceedings of the Edinburgh Mathematical Society. 32, 2, p. 317-327 11 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  62. Published

    On the vanishing of Hn(A, A*) for certain C*-algebras

    Christensen, Erik & Sinclair, A. M., Mar 1989, In: Pacific Journal of Mathematics. 137, 1, p. 55-63 9 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  63. 1988
  64. Published

    Close operator algebras

    Christensen, Erik, 1988, In: NATO ASI Series C Mathematical and Physical Sciences - Advanced Study Institute. 247 , p. 537 - 556 20 p.

    Research output: Contribution to journalConference articleResearchpeer-review

  65. 1987
  66. Published

    Completely bounded multilinear maps and C*-algebraic cohomology

    Christensen, Erik, Effros, E. G. & Sinclair, A., Jun 1987, In: Inventiones Mathematicae. 90, 2, p. 279-296 18 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  67. Published

    Representations of completely bounded multilinear operators

    Christensen, Erik & Sinclair, A. M., May 1987, In: Journal of Functional Analysis. 72, 1, p. 151-181 31 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  68. Published

    The algebra of generalized compacts associated with a von Neumann algebra

    Christensen, Erik, 1987, Operator Theory: Advances and applications.. Birkhäuser Verlag, Vol. 24. p. 51 - 58 8 p.

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

  69. 1986
  70. Published

    Similarities of II_1 factors with property Gamma

    Christensen, Erik, 1986, In: Journal of Operator Theory. 15, 2, p. 281 - 288 8 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  71. 1984
  72. Published

    Properly infinite aw*-algebras are monotone sequentially complete

    Christensen, Erik & Pedersen, G. K., Jul 1984, In: Bulletin of the London Mathematical Society. 16, 4, p. 407-410 4 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  73. Published

    Pertrurbationer af operatoralgebraer

    Christensen, Erik, 1984, 50 p.

    Research output: Book/ReportBookResearchpeer-review

  74. 1983
  75. Published

    Completely order isomorphic and close C-algebras need not BE, *-isomorphic

    Choi, M. D. & Christensen, Erik, Nov 1983, In: Bulletin of the London Mathematical Society. 15, 6, p. 604-610 7 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  76. 1982
  77. Published

    Measures on projections and physical states

    Christensen, Erik, Dec 1982, In: Communications in Mathematical Physics. 86, 4, p. 529-538 10 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  78. Published

    Derivations and their relation to perturbations of operator algebras

    Christensen, Erik, 1982, American Mathematical Society Symposia . Vol. 38. p. 261 - 273 13 p.

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

  79. Published

    Extensions of derivations II

    Christensen, Erik, 1982, In: Mathematica Scandinavica. 50, p. 111 -122 12 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  80. 1981
  81. Published

    On non-selfadjoint representations of C*-algebras

    Christensen, Erik, 1981, In: American Journal of Mathematics. 103, p. 817 - 833 17 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  82. 1980
  83. Published

    Near inclusions of C*-algebras

    Christensen, Erik, Jul 1980, In: Acta Mathematica. 144, 1, p. 249-265 17 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  84. Published

    Commutants of nest algebras modulo the compact operators

    Christensen, Erik & Peligrad, C., Feb 1980, In: Inventiones Mathematicae. 56, 1, p. 113-116 4 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  85. 1979
  86. Published

    Subalgebras of a finite algebra

    Christensen, Erik, Feb 1979, In: Mathematische Annalen. 243, 1, p. 17-29 13 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  87. Published

    Cohomology of operator algebras and quantum dynamical semigroups.

    Christensen, Erik & Evans , D. E., 1979, In: Journal of the London Mathematical Society. 20, 2, p. 358-368 11 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  88. 1978
  89. Published

    Generators of semigroups of completely positive maps

    Christensen, Erik, Jun 1978, In: Communications in Mathematical Physics. 62, 2, p. 167-171 5 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  90. Published

    Extension of derivations

    Christensen, Erik, Feb 1978, In: Journal of Functional Analysis. 27, 2, p. 234-247 14 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  91. 1977
  92. Published

    Derivations of nest algebras

    Christensen, Erik, Jun 1977, In: Mathematische Annalen. 229, 2, p. 155-161 7 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  93. Published

    Perturbation of operator algebras

    Christensen, Erik, Feb 1977, In: Inventiones Mathematicae. 43, 1, p. 1-13 13 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  94. Published

    Perturbations of operator algebras II.

    Christensen, Erik, 1977, In: Indiana University Mathematics Journal. 26, p. 891 - 904 14 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  95. 1975
  96. Published

    Perturbations of type I von neumann algebras

    Christensen, Erik, Jan 1975, In: Journal of the London Mathematical Society. s2-9, 3, p. 395-405 11 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

  97. 1972
  98. Published

    Non-commutative integration for monotone sequentially closed C∗ algebras

    Christensen, Erik, 1972, In: Mathematica Scandinavica. 31, p. 171-190 20 p.

    Research output: Contribution to journalJournal articleResearchpeer-review

ID: 4394