On the Pythagoras number for polynomials of degree 4 in 5 variables

• Santiago Laplagne ^[1]
  1. [1] Universidad de Buenos Aires

     Universidad de Buenos Aires

     Argentina

     
• Localización: Revista de la Unión Matemática Argentina, ISSN 0041-6932, ISSN-e 1669-9637, Vol. 68, Nº. 1, 2025, págs. 343-348
• Idioma: inglés
• DOI: 10.33044/revuma.4224
• Enlaces
  • Texto completo
• Resumen

  • We give an example of a polynomial of degree 4 in 5 variables that is the sum of squares of 8 polynomials and cannot be decomposed as the sum of 7 squares. This improves the current existing lower bound of 7 polynomials for the Pythagoras number p(5, 4).

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