Now showing items 1-10 of 10

    • ÀLGEBRA 2 (Examen 2n quadrim) 

      Vela del Olmo, Maria Montserrat (Universitat Politècnica de Catalunya, 2004-06-03)
      Exam
      Restricted access to the UPC academic community
    • ÀLGEBRA 2 (Examen 2n quadrim) 

      Vela del Olmo, Maria Montserrat (Universitat Politècnica de Catalunya, 2004-07-01)
      Exam
      Restricted access to the UPC academic community
    • COMPUTACIÓ ALGEBRAICA (Examen 2n quadrim) 

      Vela del Olmo, Maria Montserrat
      Exam
      Restricted access to the UPC academic community
    • From Galois to Hopf Galois: theory and practice 

      Crespo Vicente, Teresa; Río Doval, Ana; Vela del Olmo, Maria Montserrat (2015-09)
      Article
      Open Access
      Hopf Galois theory expands the classical Galois theory by con- sidering the Galois property in terms of the action of the group algebra k [ G ] on K/k and then replacing it by the action of a Hopf algebra. We review the ...
    • Hopf Galois structures on symmetric and alternating extensions 

      Río Doval, Ana; Vela del Olmo, Maria Montserrat; Crespo Vicente, Teresa (2018)
      Article
      Open Access
      By using a recent theorem by Koch, Kohl, Truman and Underwood on normality, we determine that some types of Hopf Galois structures do not occur on Galois extensions with Galois group isomorphic to alternating or symmetric ...
    • Induced Hopf Galois structures 

      Crespo Vicente, Teresa; Río Doval, Ana; Vela del Olmo, Maria Montserrat (2016-07-01)
      Article
      Open Access
      For a ¿nite Galois extension K/k and an intermediate ¿eld F such that Gal(K/F)has a normal complement in Gal(K/k), we construct and characterize Hopf Galois structures on K/k which are induced by a pair of Hopf Galois ...
    • Non-isomorphic Hopf Galois structures with isomorphic underlying Hopf algebras 

      Crespo, Teresa; Río Doval, Ana; Vela del Olmo, Maria Montserrat (2014-10-30)
      Article
      Restricted access - publisher's policy
      We give a degree 8 non-normal separable extension having two non-isomorphic Hopf Galois structures with isomorphic underlying Hopf algebras.
    • On the Galois correspondence theorem in separable Hopf Galois theory 

      Crespo Vicente, Teresa; Río Doval, Ana; Vela del Olmo, Maria Montserrat (2016-01)
      Article
      Open Access
      In this paper we present a reformulation of the Galois correspondence theorem of Hopf Galois theory in terms of groups carrying farther the description of Greither and Pareigis. We prove that the class of Hopf Galois ...
    • On the Galois embedding problem associated to the universal central extension of the alternating group of degree 6 

      Crespo, Teresa; Vela del Olmo, Maria Montserrat (2013)
      Article
      Open Access
      We obtain an explicit expression for the obstruction to the solvability of the Galois embedding problem associated to the universal central extension of the alternating group of degree 6.
    • The Hopf Galois property in subfield lattices 

      Crespo Vicente, Teresa; Río Doval, Ana; Vela del Olmo, Maria Montserrat (2016-01-01)
      Article
      Open Access
      Let K/k be a finite separable extension, n its degree and (K) over tilde /k its Galois closure. For n <= 5, Greither and Pareigis show that all Hopf Galois extensions are either Galois or almost classically Galois and they ...