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Ana Portilla, Ph.D.


Department of Mathematics and Computer Science
Mathematics


Education

  • Ph.D. Mathematics, Universidad Carlos III, Madrid (Spain)
  • M.S. Mathematics, Universidad Complutense de Madrid (Spain)

Practice Areas

  • Complex Analysis
  • Geometric Function Theory
  • Graph Theory

Publications and Media Placements

The names of the authors are listed in alphabetical order.

  • P. Bosch, A. Portilla, J.M. Rodríguez, J.M. Sigarreta, On a generalization of the Opial inequality, Demonstratio Mathematica 57(1) 20230149 (2024).
  • A. Granados, D. Pestana, A. Portilla, J. M. Rodríguez, E. Tourís, Liouville property and quasi-isometries on negatively curved Riemannian surfaces, Proceedings of the Royal Society of Edinburgh Section A: Mathematics 1-23 (2023).
  • J.M. Rodríguez, A. Granados, A. Portilla ¿Por qué lo llaman estadística cuando quieren decir sesgo? The Conversation; BBC; El Economista (2023).
  • Y. Quintana, A. Granados, A. Portilla Â¿Y si en las elecciones generales contáramos los votos como los suecos? The Conversation (2023).
  • Carballosa, A. Granados, J.A. Méndez-Bermúdez, D. Pestana, A. Portilla, Computational properties of the arithmetic-geometric index, Journal of Mathematical Chemistry, 60 (2022): 1854-1871.
  • Granados, D. Pestana, A. Portilla, J.M. Rodriguez, Stability of p-parabolicity under quasi-isometries, Mathematische Nachrichten (2022).
  • J. Gonzalo, A. Portilla, J.M. Rodríguez and E. Tourís, A decomposition for plane domains with the quasihyperbolic metric, Journal of Mathematical Analysis and Applications 502 (2021) 125227.
  • A. Granados, A. Portilla, J.M. Rodríguez and J.M. Sigarreta, Inequalities on the Geometric-Arithmetic Index, Hacettepe Journal of Mathematics and Statistics 50(3) 778-794 (2021)
  • A. Portilla, J. M. Rodríguez, J. M. Sigarreta, E. Touris  Gromov hyperbolicity in directed graphs.  Symmetry 12(1), 105 (2020). Special issue "Protection of graphs".
  • A. Granados, D. Pestana, A. Portilla, J. M. Rodríguez, E. Touris  Stability of the volume growth rate under quasi-isometries.  Revista Matemática Complutense (2019) 1-40.
  • W. Carballosa, A. Granados, D. Pestana, A. Portilla, J. M. Rodríguez, J. M. Sigarreta Relations between some topological índices and the line graph.  Journal of Mathematical Chemistry 58(3) (2019) 1-15.
  • A. Portilla, J. M. Rodríguez, J. M. Sigarreta Recent lower bounds for Geometric-Arithmetic Index.  Discrete Mathematics Letters (1) (2019) 59-82.
  • A. Granados, A. Portilla La función exponencial planta cara a la homeopatía, Revista SUMA 93 (2019).
  • A. Granados, A. Portilla La vacuna solidaria: las matemáticas demuestran que 93=100%, El Escéptico: la revista para el fomento de la razón y la ciencia 51, Invierno 2019.
  • A. Granados, D. Pestana, A. Portilla, J.M. Rodríguez, E. Touris Stability on the Injectivity Radius under Quasi-isometries and Applications to Isoperimetric Inequalities. Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A. Matemáticas 112(4) (2018), 1225-1247.
  • A. Portilla, A. Granados La homeopatía suspende matemáticas.  The Conversation; Público; Cadena Ser (2018).
  • A. Granados, D. Pestana, A. Portilla, J.M. Rodríguez Gromov Hyperbolicity in Mycielskian Graphs. Symmetry (2017), 9(8), 131.
  • A. Portilla, J. M. Rodríguez, J. M. Sigarreta, J.-M. Vilaire  Gromov hyperbolic tessellation graphs. Utilitas Mathematica Vol. 97 (2015) 193-212.
  • A. Cantón, A. Granados, A. Portilla, J.M. Rodríguez. Quasi-isometries and isoperimetric inequalities in planar domains.  Journal of the Mathematical Society of Japan. 67, No. 1 (2015) 127–157.
  • Walter Carballosa, Ana Portilla, J.M. Rodríguez, J.M. Sigarreta. Planarity and Hyperbolicity in Graphs. Graphs and Combinatorics. DOI: 10.1007/s00373-014-1459-4.
  • Alicia Cantón, Ana Granados, Ana Portilla, José M. Rodríguez. Isoperimetric inequalities in graphs and surfaces. Electronic Notes on Discrete Mathematics. Sept 2014 (Vol : 46) pp. 257-264. DOI: 10.1016/j.endm.2014.08.034.
  • J. Gonzalo, A. Portilla, J.M. Rodríguez, E. Tourís. The Topology of balls in Riemannian surfaces and Gromov hyperbolicity. Mathematische Zeitschrift 275(3) (2013), 741-760.
  • Peter Hästö , A. Portilla, J.M. Rodríguez, E. Tourís. Gromov hyperbolicity of Denjoy domains through fundamental domains. Publicationes Mathematicae Debrecen 80/3-4 (2012), 295-310.
  • A. Portilla, Yamilet Quintana, J. M. Rodríguez, E. Tourís. Concerning asymptotic behavior for external polynomials associated to non-diagonal Sobolev norms. Journal of Function Spaces and Applications, Volume 2013 (2013), Article ID 628031, 11 pages.
  • P. Hästö, H. Linden, A. Portilla, J.M. Rodríguez, E. Tourís, Gromov hyperbolicity of Denjoy domains with hyperbolic and quasihyperbolic metrics. Journal of the Mathematical Society of Japan 64 (2012), 245-259.
  • A. Portilla, J.M. Rodríguez, E. Tourís, Structure Theorem for Riemannian surfaces with arbitrary curvatureMathematische Zeitschrift. 271 (2012), 45-62.
  • A. Portilla, J.M. Rodríguez, E. Tourís, A very simple characterization of Gromov hyperbolicity for a special kind of Denjoy Domains. Journal of the Korean Mathematical Society 48 (2011), 565-583.
  • P. Hästö, A. Portilla, J.M. Rodríguez, E. Tourís, Uniformly separated sets and Gromov hyperbolicity of domains with the quasihyperbolic metric. Mediterranean Journal of Mathematics nº1, 8 (2011), 47-65.
  • A. Portilla, J.M. Rodríguez, E. Tourís, A real variable characterization of Gromov hyperbolicity of flute surfaces. Osaka Journal of Mathematics 48 (2011) 47-65.
  • A. Portilla, Y. Quintana, J.M. Rodríguez, E. Tourís, Zero location and asymptotic behavior for extremal polynomials with non-diagonal Sobolev norms. Journal of Approximation Theory 162 (2010), 2225-2242.
  • P. Hästö, A. Portilla, J.M. Rodríguez, E. Tourís, Gromov hyperbolic equivalence of the hyperbolic and the quasihyperbolic metrics in Denjoy domains. Bulletin London Mathematical Society 42 (2010), 282-294.
  • A. Portilla, J.M. Rodríguez, E. Tourís. The multiplication operator, zero location and asymptotic for non-diagonal Sobolev norms. Acta Applicandae Mathematicae 111 (2010), 205-218.
  • A. Portilla, J.M. Rodríguez, E. Tourís. Stability of Gromov hyperbolicity. Journal of Advanced Mathematical Studies 2 (2009), 1-20.
  • P. Hästö, A. Portilla, J.M. Rodríguez, E. Tourís. Comparative Gromov hyperbolicity results for the hyperbolic and quasihyperbolic metrics. Complex Variables and Elliptic Equations 55 (2010), 127-135.
  • A. Portilla, E. Tourís. A characterization of Gromov hyperbolicity of surfaces with variable negative curvature. Publicacions Mathematiques.  53 (2009), 83-110.
  • A. Portilla, Y. Quintana, J.M. Rodríguez, E. Tourís, Weierstrass' Theorem in weighted Sobolev spaces with k derivatives. The Rocky Mountain Journal of Mathematics 37 (2007) 1989-2024.
  • A. Portilla, Y. Quintana, J.M. Rodríguez, E. Tourís, Weierstrass' Theorem with first derivatives. Journal of Mathematical Analysis and Applications 334 (2007) 1167-1198.
  • V. Ãlvarez, A. Portilla, J.M. Rodríguez y E. Tourís, Gromov hyperbolicity of Denjoy Domains. Geometriae Dedicata 121 (2006) 221-245.
  • A. Portilla, Y. Quintana, J.M. Rodríguez y E. Tourís, Weierstrass’ Theorem in weighted Sobolev spaces with k derivatives; announcement of results. Electronic Transactions in Numerical Analysis 24 (2006) 103-107.
  • A. Portilla, J.M. Rodríguez y E. Tourís, The role of funnels and punctures in the Gromov hyperbolicity of Riemann surfaces. Proceedings of the Edinburgh Mathematical Society 49 (2006), 399-425.
  • A. Portilla, Y. Quintana, J.M. Rodríguez, E. Tourís, Weierstrass' Theorem with weights. Journal of Approximation Theory 127 (2004), 83-107.
  • A. Portilla, J.M. Rodríguez y E. Tourís, The topology of balls and Gromov hyperbolicity of Riemann surfaces. Differential Geometry and Applications 21 (2004), 317-335.
  • A. Portilla, J.M. Rodríguez y E. Tourís, Gromov hyperbolicity through decomposition of metric spaces II. The Journal of Geometric Analysis 14 (2004), 123-149.
  • D. Pestana, J.M. Rodríguez, E. Romera, E. Touris, V. Ãlvarez y A. Portilla, (Libro) Un Curso práctico de Cálculo y Precálculo, Ariel Ciencia (2000).