Tapio Rajala
Ph.D., University of Jyväskylä, 2009
Title of Docent, University of Jyväskylä, 2012
Academy Research Fellow
University of Jyväskylä




Research interests

I am interested in geometric analysis and geometric measure theory in metric measure spaces. Here are some of the topics I have recently studied.

From summer 2014 until summer 2019 my research is funded by the Academy of Finland, Academy Research Fellow project Local and global structure of metric measure spaces with Ricci curvature lower bounds. Previously my research was funded by the Academy of Finland, postdoctoral project Geometric properties of sets and measures: densities, rectifiability and constructions from the summer 2011 until the end of 2013. Before this I was a postdoc at the Scuola Normale Superiore di Pisa working in the European Project Geometric Measure Theory in non Euclidean spaces.

Events

27th Jyväskylä Summer School and MAnET-workshop (7th-18th August, 2017)
Workshop: Optimal transport meets density functional theory (31st May - 7th June, 2017)

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Papers and notes

These are the preliminary versions of my publications. Notice that they might differ from the published ones. Some information related to my publications can also be found in my profile at MathSciNet (requires surbscription) and at Google Scholar.

    Preprints

  1. Products of snowflaked Euclidean lines are not minimal for looking down
    (with M. Joseph), Preprint, 2017, 21 pp.
  2. Removable sets for intrinsic metric and for holomorphic functions
    (with S. Kalmykov and L. V. Kovalev), Preprint, 2017, 23 pp.
  3. Planar W1,1-extension domains
    (with P. Koskela and Y. Zhang), Preprint, 2017, 44 pp.
  4. A geometric characterization of planar Sobolev extension domains
    (with P. Koskela and Y. Zhang), Preprint, 2015, 33 pp.

    Accepted

  5. Isometric embeddings of snowflakes into finite-dimensional Banach spaces
    (with E. Le Donne and E. Walsberg), Proc. Amer. Math. Soc., to appear.
  6. Ahlfors-regular distances on the Heisenberg group without biLipschitz pieces
    (with E. Le Donne and S. Li), Proc. Lond. Math. Soc., to appear.

    Published

  7. A density problem for Sobolev spaces on Gromov hyperbolic domains
    (with P. Koskela and Y. Zhang), Nonlinear Anal., 154 (2017), 189-209.
  8. Local homogeneity and dimensions of measures
    (with A. Käenmäki and V. Suomala), Ann. Sc. Norm. Super. Pisa Cl. Sci., 16 (2016), no. 4, 1315-1351.
  9. Optimal maps and exponentiation on finite dimensional spaces with Ricci curvature bounded from below
    (with N. Gigli and K.-T. Sturm), J. Geom. Anal., 26 (2016), no. 4, 2914-2929.
  10. Tangent lines and Lipschitz differentiability spaces
    (with F. Cavalletti), Anal. Geom. Metr. Spaces, 4 (2016), no. 1, 85-103.
  11. L estimates in optimal mass transportation
    (with H. Jylhä), J. Funct. Anal., 270 (2016), 4297-4321.
  12. Failure of the local-to-global property for CD(K,N) spaces
    Ann. Sc. Norm. Super. Pisa Cl. Sci., 16 (2016), 45-68.
  13. A function whose graph has positive doubling measure
    (with T. Ojala), Proc. Amer. Math. Soc., 144 (2016), no. 2, 733-738.
  14. Euclidean spaces as weak tangents of infinitesimally Hilbertian metric measure spaces with Ricci curvature bounded below
    (with N. Gigli and A. Mondino), J. Reine Angew. Math., 705 (2015), 233-244.
  15. Riemannian Ricci curvature lower bounds in metric measure spaces with σ-finite measure
    (with L. Ambrosio, N. Gigli and A. Mondino), Trans. Amer. Math. Soc., 367 (2015), no. 7, 4661-4701.
  16. Failure of topological rigidity results for the measure contraction property
    (with C. Ketterer), Potential Anal., 42 (2015), no. 3, 645-655.
  17. Assouad dimension, Nagata dimension, and uniformly close metric tangents
    (with E. Le Donne), Indiana Univ. Math. J., 64 (2015), no. 1, 21-54.
  18. Radon-Nikodym property and area formula for Banach homogeneous group targets
    (with V. Magnani), Int. Math. Res. Notices, 2014 (2014), no. 23, 6399-6430.
  19. Non-branching geodesics and optimal maps in strong CD(K,∞)-spaces
    (with K.-T. Sturm), Calc. Var. Partial Differential Equations, 50 (2014), no. 3-4, 831-846.
  20. Slopes of Kantorovich potentials and existence of optimal transport maps in metric measure spaces
    (with L. Ambrosio), Ann. Mat. Pura Appl., 193 (2014), no. 1, 71-87.
  21. Local multifractal analysis in metric spaces
    (with A. Käenmäki and V. Suomala), Nonlinearity, 26 (2013), no. 8, 2157–2173.
  22. Improved geodesics for the reduced curvature-dimension condition in branching metric spaces
    Discrete Contin. Dyn. Syst., 33 (2013), no. 7, 3043-3056.
  23. Interpolated measures with bounded density in metric spaces satisfying the curvature-dimension conditions of Sturm
    J. Funct. Anal., 263 (2012), no. 4, 896-924.
  24. Local Poincaré inequalities from stable curvature conditions on metric spaces
    Calc. Var. Partial Differential Equations, 44 (2012), no. 3-4, 477-494.
  25. Thin and fat sets for doubling measures in metric spaces
    (with T. Ojala and V. Suomala), Studia Math., 208 (2012), no. 3, 195-211.
  26. Existence of doubling measures via generalised nested cubes
    (with A. Käenmäki and V. Suomala), Proc. Amer. Math. Soc., 140 (2012), no. 9, 3275-3281.
  27. Generalized Hausdorff dimension distortion in Euclidean spaces under Sobolev mappings
    (with A. Zapadinskaya and T. Zürcher), J. Math. Anal. Appl., 384 (2011), no. 2, 468-477.
  28. Generalized dimension distortion under mappings of sub-exponentially integrable distortion
    (with A. Zapadinskaya and T. Zürcher), Ann. Acad. Sci. Fenn. Math., 36 (2011), no. 2, 553-566.
  29. Planar Sobolev homeomorphisms and Hausdorff dimension distortion
    Proc. Amer. Math. Soc., 139 (2011), no. 5, 1825-1829.
  30. Comparing the Hausdorff and packing measures of sets of small dimension in metric spaces
    Monatsh. Math., 164 (2011), no. 3, 313-323.
  31. Weakly controlled Moran constructions and iterated functions systems in metric spaces
    (with M. Vilppolainen), Illinois J. Math., 55 (2011), no. 3, 1015-1051.
  32. Upper conical density results for general measures on Rn
    (with M. Csörnyei, A. Käenmäki and V. Suomala), Proc. Edinb. Math. Soc., 53 (2010), no. 2, 311-331.
  33. Packing dimension and Ahlfors regularity of porous sets in metric spaces
    (with E. Järvenpää, M. Järvenpää, A. Käenmäki, S. Rogovin and V. Suomala),
    Math. Z., 266 (2010), no. 1, 83-105.
  34. Large porosity and dimension of sets in metric spaces
    Ann. Acad. Sci. Fenn. Math., 34 (2009), no. 2, 565-581.
  35. Packing dimension of mean porous measures
    (with D. Beliaev, E. Järvenpää, M. Järvenpää, A. Käenmäki, S. Smirnov and V. Suomala),
    J. Lond. Math. Soc. (2), 80 (2009), no. 2, 514-530.

    Other

  36. Porosity and dimension of sets and measures
    (Introductory part of the Ph.D. thesis), Rep. Univ. Jyväskylä Dept. Math. Stat. 119 (2009).
  37. A note on the level sets of Hölder continuous functions on the real line
    (A short note from 2008), 6 pp.
  38. Dimension of mean porous measures
    Real Analysis Exchange 2007, 31st Summer Symposium Conference, 257-262.
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Teaching

In the spring 2018 I am giving a course on Alexandov spaces.

I have previously taught the courses
Advanced Measure Theory (2016), Optimal Mass Transportation (2014), Functional Analysis (2014), Basics in Number Theory (2013), Number Theory (2010), Introduction to Mathematics (2010), Symbolic Mathematics (2008 and 2009)

and acted as a teaching assistant on the courses
Measure and Integration Theory 1 & 2 (2007), Linear Algebra and Geometry 1 (2006), Analysis 2 (2006), Approbatur 3 (2005), Analysis 1 (2004), Euclidean Spaces (2004), Vectors and Matrices (2003).

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- last update 10.8.2017 -