Henrik Stetkær

Research output

Research output per year 2001 2001 2002 2003 2004 2006 2015 2024

• 32 Journal article
• 8 Literature review
• 8 Working paper
• 5 Conference abstract in proceedings
• 3 More
  • 2 Book
  • 1 Book chapter

Research output per year

Research output per year

Search results

• 2024

  The cosine addition and subtraction formulas on non-abelian groups: Addition and subtraction formulas: O. Ajebbar et al.

  Ajebbar, O., Elqorachi, E. & Stetkær, H., Dec 2024, In: Aequationes Mathematicae. 98, 6, p. 1657-1676 20 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  • Abelian Group 100%
  • Cosine 100%
  • Non-abelian Group 100%
  • Cosine Addition Law 50%
  • Topological Groups 33%

• The equation f(xy)=f(x)h(y)+g(x)f(y) and representations on C²

  Stetkær, H., Oct 2024, In: Aequationes Mathematicae. 98, 5, p. 1419-1438 20 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  • Topological Group 100%
  • Complex-valued Function 100%
  • Sine Subtraction Law 100%
  • Levi-Civita Equation 100%
  • Involution 100%
  1 Citation (Scopus)
• 2023

  Exponential polynomials and the sine addition law on magmas

  Stetkær, H., Dec 2023, In: Aequationes Mathematicae. 97, 5-6, p. 963-979 17 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  File

  • Addition Law 100%
  • Exponential Polynomial 100%
  • Abelian Group 33%
  • Polynomial Solution 33%
  • Complex Vector Space 33%
  1 Citation (Scopus)

  1 Downloads (Pure)
• 2022

  A Levi–Civita functional equation on semigroups

  Stetkær, H., Feb 2022, In: Aequationes Mathematicae. 96, p. 115-127

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Functional Equation 100%
  • Semigroup 100%
  • Multiplicative Function 100%
  • Addition Law 50%
  1 Citation (Scopus)

• Homomorphisms of Product Semigroups

  Stetkær, H., Apr 2022, In: Results in Mathematics. 77, 2, 60.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Semigroup 100%
  • Homomorphism 100%
  • Sufficient Condition 33%
  5 Citations (Scopus)
• 2021

  k-Valued Wilson functions

  Stetkær, H., Dec 2021, In: Aequationes Mathematicae. 95, 6, p. 1131-1147 17 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Functional Equation 100%
  • Algebraically Closed Field 50%
  • Compact Group 50%
  • Semigroup 50%
  • Finite Group 50%

• The small dimension lemma and d'Alembert's equation on semigroups

  Stetkaer, H., Apr 2021, In: Aequationes Mathematicae. 95, 2, p. 281-299 19 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • D'Alembert 100%
  • Small Dimension 100%
  • Semigroup 100%
  • Algebraically Closed Field 50%
  • Multiplicative Function 50%
  12 Citations (Scopus)
• 2020

  More about Wilson’s functional equation

  Stetkær, H., Jun 2020, In: Aequationes Mathematicae. 94, 3, p. 429-446 18 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  File

  • Functional Equation 100%
  • Multiplicative Function 100%
  • Nilpotent 50%
  10 Citations (Scopus)

  57 Downloads (Pure)
• 2019

  Extensions of the sine addition law on groups

  Stetkær, H., 2019, In: Aequationes Mathematicae. 93, 2, p. 467-484 18 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Unknown Function 100%
  • Addition Law 100%
  • Functional Equation 50%
  11 Citations (Scopus)
• 2018

  Extensions of the Sine Addition Formula on Monoids

  Ebanks, B. & Stetkær, H., 1 Sept 2018, In: Results in Mathematics. 73, 3, 119.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Multiplicative Function 100%
  • Monoids 100%
  • Semigroup 33%
  • Linear Combination 33%
  • Unknown Function 33%
  2 Citations (Scopus)
• 2017

  A note on Wilson’s functional equation

  Stetkær, H., 1 Oct 2017, In: Aequationes Mathematicae. 91, 5, p. 945-947 3 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  File

  • Functional Equation 100%
  • Semigroup 33%
  9 Citations (Scopus)

  166 Downloads (Pure)

• Kannappan’s functional equation on semigroups with involution

  Stetkær, H., 1 Feb 2017, In: Semigroup Forum. 94, 1, p. 17-30 14 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  File
  15 Citations (Scopus)

  247 Downloads (Pure)

• The kernel of the second order Cauchy difference on semigroups

  Stetkær, H., 1 Apr 2017, In: Aequationes Mathematicae. 91, 2, p. 279–288 10 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  Open Access

  File

  • Cauchy's Equation 100%
  11 Citations (Scopus)

  225 Downloads (Pure)
• 2016

  A link between Wilson’s and d’Alembert’s functional equations

  Stetkær, H., 2016, In: Aequationes Mathematicae. 90, 2, p. 407-409 3 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  10 Citations (Scopus)

• The cosine addition law with an additional term

  Stetkær, H., Dec 2016, In: Aequationes Mathematicae. 90, 6, p. 1147–1168 22 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  9 Citations (Scopus)

• Van Vleck’s functional equation for the sine

  Stetkær, H., 2016, In: Aequationes Mathematicae. 90, 1, p. 25-34 10 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  20 Citations (Scopus)
• 2015

  A Variant of d'Alembert's Functional Equation

  Stetkær, H., 2015, In: Aequationes Mathematicae. 89, 3, p. 657-662 6 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  44 Citations (Scopus)

• d'Alembert's other functional equation

  Ebanks, B. & Stetkaer, H., 2015, In: Publicationes mathematicae-Debrecen. 87, 3-4, p. 319-349 31 p., 6.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Functional Equation 100%
  • Matrix (Mathematics) 50%
  • Topological Groups 50%
  • Abelian Case 50%
  • Connected Lie Group 50%
  6 Citations (Scopus)

• d’Alembert’s other functional equation on monoids with an involution

  Ebanks, B. & Stetkær, H., 2015, In: Aequationes Mathematicae. p. 187-206 20 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  54 Citations (Scopus)

• On Wilson's functional equations

  Ebanks, B. & Stetkaer, H., 2015, In: Aequationes Mathematicae. 89, 2, p. 339-354 16 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Functional Equation 100%
  • Elements of Matrix 50%
  • Additive Character 50%
  • Irreducibles 50%
  27 Citations (Scopus)
• 2010

  Continuous cocycles on locally compact groups: II

  Ebanks, B. & Stetkær, H., 2010, In: Aequationes Mathematicae. 80, 1-2, p. 57-83 27 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  3 Citations (Scopus)
• 2009

  Continuous cocycles on locally compact groups

  Ebanks, B. & Stetkær, H., 2009, In: Aequationes Mathematicae. 78, 1-2, p. 123-145 23 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Cocycle 100%
  • Locally Compact Group 100%
  • Lie Group 50%
  • Functional Equation 50%
  • Cohomology Group 50%
  5 Citations (Scopus)

• Properties of d'Alembert functions

  Stetkær, H., 2009, In: Aequationes Mathematicae. 77, 3, p. 281 - 301 21 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  13 Citations (Scopus)
• 2007

  Representations, convolution square roots and spherical vectors

  Stetkær, H., 2007, In: Journal of Functional Analysis. 252, p. 1-33 33 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  2 Citations (Scopus)
• 2006

  On the quadratic functional equation on groups

  Friis, P. D. P. & Stetkær, H., 2006, In: Publ. Math. Debrecen. 69, 1-2, p. 65-93

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  • Functional Equation 100%
  • Explicit Formula 50%
  • Quotient Group 50%
  • Sufficient Condition 50%
  13 Citations (Scopus)
• 2005

  Functional equations and matrix-valued spherical functions

  Stetkær, H., 2005, In: Aequationes Mathematicae. 69, p. 271-292 22 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  20 Citations (Scopus)

• Operator-valued spherical functions

  Stetkær, H., 2005, In: Journal of Functional Analysis. 224, p. 338-351 14 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  14 Citations (Scopus)
• 2004

  D'Alembert's and Wilson's functional equations on step 2 nilpotent groups

  Stetkær, H., 2004, In: Aequationes Mathematicae. 67, 3, p. 241-262 22 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
  31 Citations (Scopus)

• On a variant of Wilson's functional equation on groups

  Stetkær, H., 2004, In: Aequationes Mathematicae. 68, p. 160-176 17 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  15 Citations (Scopus)
• 2003

  On Jensen's functional equation on groups

  Stetkær, H., 2003, In: Aequationes Mathematicae. 66, p. 100-118 19 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  14 Citations (Scopus)
• 2002

  On the Cosine-Sine Functional Equation on Groups

  Friis, P. D. P. & Stetkær, H., 2002, In: Aequationes Mathematicae. 64, 1-2, p. 145-164 20 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

  11 Citations (Scopus)
• 2001

  On multiplicative maps

  Stetkær, H., 2001, In: Semigroup Forum. 63, 3, p. 466-468 3 p.

  Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review