Skip to main content
Log in

Nesbitt and Shapiro cyclic sum inequalities for positive definite matrices

  • Original Paper
  • Published:
Advances in Operator Theory Aims and scope Submit manuscript

Abstract

The aim of this note is to show that certain number theoretic inequalities, due to Nesbitt and Shapiro, have noncommutative counterparts involving positive definite matrices.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Abadir, K.M., Magnus, J.R.: Matrix Algebra. Cambridge University Press, New York (2005)

    Book  Google Scholar 

  2. Albert, A.: Conditions for positive and nonnegative definitions in terms of pseudoinverses. SIAM J. Appl. Math. 17, 434–440 (1969)

    Article  MathSciNet  Google Scholar 

  3. Bhatia, R.: Positive Definite Matrices. Princeton University Press, Princeton (2007)

    MATH  Google Scholar 

  4. Choudhury, P.N., Sivakumar, K.C.: An extension of a matrix inequality of Thompson. Linear Algebra Appl. 535, 151–159 (2017)

    Article  MathSciNet  Google Scholar 

  5. Daykin, D.E.: Inequalities for functions of a cyclic nature. J. Lond. Math. Soc. 3, 453–462 (1971)

    Article  MathSciNet  Google Scholar 

  6. Diananda, P.H.: On a cyclic sum. Proc. Glasgow Math. Assoc. 6, 11–13 (1963)

    Article  MathSciNet  Google Scholar 

  7. Djoković, D.Ž: Sur une inégalité. Proc. Glasgow Math. Assoc. 6, 1–10 (1963)

    Article  MathSciNet  Google Scholar 

  8. Godunova, E.K., Levin, V.I.: A cyclic sum with twelve terms. Mat. Zametki 19, 873–885 (1976)

    MathSciNet  Google Scholar 

  9. Lin, M.: On Drury’s solution of Bhatia and Kittaneh’s question. Linear Algebra Appl. 528, 33–39 (2017)

    Article  MathSciNet  Google Scholar 

  10. Malcolm, M.A.: A note on a conjecture of L. J. Mordell. Math. Comput. 25, 375–377 (1971)

    Article  MathSciNet  Google Scholar 

  11. Mordell, L.J.: On the inequality \(\sum \limits ^{n}_{r=1} \, x_{r}/(x_{r+1}+x_{r+2})\ge n/2\) and some other. Abh. Math. Sem. Univ. Hamb. 22, 229–241 (1958)

    Article  Google Scholar 

  12. Nesbitt, A.M.: Problem 15114. Educ. Times 3, 37–38 (1903)

    MATH  Google Scholar 

  13. Nowosad, P.: Isoperimetric eigenvalue problems in algebras. Commun. Pure Appl. Math. 21, 401–465 (1968)

    Article  MathSciNet  Google Scholar 

  14. Searcy, J.L., Troesch, B.A.: A cyclic inequality and a related eigenvalue problem. Pac. J. Math. 81, 217–226 (1979)

    Article  MathSciNet  Google Scholar 

  15. Shapiro, H.S.: Problem 4603. Am. Math. Mon. 61, 571 (1954)

    Article  Google Scholar 

  16. Troesch, B.A.: On Shapiro’s cyclic inequality for \(N=13\). Math. Comput. 45, 199–207 (1985)

    MathSciNet  MATH  Google Scholar 

  17. Troesch, B.A.: The validity of Shapiro’s cyclic inequality. Math. Comput. 53, 657–664 (1989)

    MathSciNet  MATH  Google Scholar 

  18. Zhang, F.: Matrix Theory: Basic Results and Techniques. Springer, New York (2011)

    Book  Google Scholar 

  19. Zulauf, A.: On a conjecture of L. J. Mordell. Abh. Math. Sem. Univ. Hamb. 22, 240–241 (1958)

    MathSciNet  MATH  Google Scholar 

Download references

Acknowledgements

We thank Apoorva Khare for a detailed reading of an earlier draft and for providing valuable comments and feedback. We also thank anonymous referees for their helpful comments. P. N. Choudhury is supported by National Post-Doctoral Fellowship (PDF/2019/000275), from SERB, Government of India. K. C. Sivakumar acknowledges funds received from MATRICS (MTR/2018/001132) of SERB, Government of India.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Projesh Nath Choudhury.

Additional information

Communicated by Qingxiang Xu.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Choudhury, P.N., Sivakumar, K.C. Nesbitt and Shapiro cyclic sum inequalities for positive definite matrices. Adv. Oper. Theory 7, 7 (2022). https://doi.org/10.1007/s43036-021-00171-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s43036-021-00171-0

Keywords

Mathematics Subject Classification

Navigation