My research area is geometric function theory. I am interested in the connection between inequalities in analysis and their geometric implications, and also in quasiconformal maps and the geometric properties of metric measure spaces conserved by them. Currently I am also involved in the studying interactions between geometry and the BV theory in metric spaces, and the utility of sets of finite perimeter in the study of Sobolev spaces.
My thesis, 1999, at the University of Michigan.
Newton-Sobolev spaces for metric measure spaces:
1.
Newtonian spaces: An extension of Sobolev spaces to metric measure spaces
appeared in
Rev. Mat. Iberoamericana, 16 (2000) 243--279.
2.
Removable sets for the Poincare inequality on metric spaces
(with
Pekka Koskela and
Heli Tuominen)
appeared in
Indiana Univ. Math. J., 49 (2000) 333--352.
3.
Modulus and continuous capacity
(with Sari kallunki)
appeared in
Ann. Acad. Sci. Fenn. Math., 26 (2001) 455--464.
4.
Sobolev classes of Banach space-valued functions and quasiconformal mappings
(with
Juha Heinonen,
Pekka Koskela, and
Jeremy Tyson)
appeared in
J. Anal. Math., 85 (2001) 87--139.
5.
Measurability of equivalence classes and $MEC_p$-property in metric spaces
(with
Esa Järvenpää, Maarit Järvenpää, Kevin Rogovin, and Sari Rogovin.)
appeared in
Rev. Mat. Iberoamericana, 23 no. 3 (2007) 811--830.
6.
Sobolev extensions of Hölder continuous and characteristic functions on
metric spaces
(with
Anders Björn and
Jana Björn)
appeared in
Canadian Journal of Mathematics, 59 (No. 6) (2007), 1135--1153.
7.
Poincare inequalities, uniform domains, and extension properties for
Newton-Sobolev spaces in metric spaces
(with
Jana Björn)
appeared in
J. Math. Anal. Appl., 332, No. 1 (2007) 190--208.
8.
Quasicontinuity of Newton--Sobolev functions and density of Lipschitz
functions in metric measure spaces
(with
Anders Björn and
Jana Björn)
appeared in
Houston J. Math., 34 No. 4 (2008) 1197--1211.
9.
Lebesgue points and capacities via boxing inequalities in metric spaces
(with
Juha Kinnunen,
Riikka Korte,
and
Heli Tuominen)
appeared in
Indiana Univ. Math. J., 57 no. 1 (2008) 401-430.
10.
Interpolation properties of Besov spaces defined on metric spaces
(with
Pekka Koskela
and
Amiran Gogatishvili)
Math. Nachr., to appear.
11.
Geometric properties of planar BV extension domains
(with
Pekka Koskela and Michele Miranda)
to appear,
Function Spaces; Topics Around the Research of Prof. Maz'ya I,
International Mathematical Series (Springer collection).
12.
The DeGiorgi measure and an obstacle problem related to
minimal surfaces in metric spaces,
(with
Juha Kinnunen,
Riikka Korte,
and
Heli Tuominen)
,
to appear in
J. Math. Pures Appl.
$p$-harmonic functions in metric measure spaces:
1.
Harmonic functions on metric spaces
appeared in
Illinois J. Math., 45 no. 3 (2001) 1021--1050.
2.
Regularity of quasi-minimizers on metric spaces
(with
Juha Kinnunen)
appeared in
Manuscripta Math., 105 (2001) 401--423.
3.
Fat sets and pointwise boundary estimates for $p$-harmonic
functions in metric spaces
(with
Jana Björn and Paul MacManus)
appeared in
J. Anal. Math., 85 (2001) 339--369.
4.
The Dirichlet problem for $p$-harmonic functions on metric measure spaces
(with
Anders Björn and
Jana Björn)
appeared in
J. Reine Angew. Math. (Crelle) 556 (2003) 173--203.
5.
Some convergence results for $p$-harmonic functions on metric measure
spaces
appeared in
the Proceedings of the London Math. Soc. 87 (2003)
226--246.
6.
The Perron method for $p$-harmonic functions in metric spaces
(with
Anders Björn and
Jana Björn)
appeared in
J. Differential Equations 195 (2003)
398--429.
7.
A problem of
Baernstein on the equality of the $p$-harmonic measure of a set
and its closure
(with
Anders Björn and
Jana Björn)
appeared in
Proc. Amer. Math. Soc. 134 (2006) 509-519.
8.
Hölder estimates of $p$-harmonic extension operators
(PDF file)
(with
Hiroaki Aikawa)
appeared in
J. Differential Equations 220 (2006) No. 1, 18--45.
9.
Polar sets on metric spaces
(with
Juha Kinnunen)
appeared in
Transactions Amer. Math. Soc.
358 (2006) 11--37.
10.
Equivalence
of AMLE, strong AMLE, and comparison with cones in metric measure
spaces (pdf file)
(with
Petri Juutinen)
appeared in
Math. Nachr. 279 (2006) 1083--1098.
11.
Maximal regularity via
reverse Holder inequalities for elliptic systems of $n$-Laplace type
involving measures,
(with
Xiao Zhong
and
Tero Kilpeläinen)
appeared in
Ark. Mat. 46 (No. 1) (2008) 77--93.
12.
Equivalence and self-improvement of $p$-fatness and Hardy's inequality,
and association with uniform perfectness
(with
Riikka Korte)
Math. Z.
, to appear.
Conformal Martin boundary:
1.
Singular functions on metric measure spaces
(with
Ilkka Holopainen)
appeared in
Collect. Math., 53 (2002) 313--332.
2.
On the conformal Martin boundary of domains in metric spaces
(with
Ilkka Holopainen and
Jeremy Tyson)
appeared in
Papers on Analysis: A volume dedicated to Olli Martio on the
occasion of his 60th birthday Report. Univ. Jyväskylä 83 (2001) 147--168.
3.
Singular behavior of conformal Martin kernels, and non-tangential
limits of conformal mappings
appeared in
Ann. Acad. Sci. Fenn. Math.
29 (2004) 195--210.
4.
Carleson type estimates for $p$-harmonic functions and the conformal Martin
boundary of John domains in metric measure spaces.
(with
Hiroaki Aikawa)
appeared in
Michigan Math. J. 53 (2005) 165--188.
5.
Boundary Harnack principle for $p$-harmonic functions in smooth
Euclidean domains
(with
Hiroaki Aikawa,
Tero Kilpeläinen,
and
Xiao Zhong),
appeared in
Potential Analysis 26 No.3 (2007) 281--301.
6.
Uniformity from Gromov hyperbolicity
(with
David Herron
and
Xiangdong Xie),
to appear in
Illinois J. Math..
Dirichlet forms on metric measure spaces:
1.
Lipschitz continuity of Cheeger-harmonic functions in metric measure
spaces
(with
Pekka Koskela and
Kai Rajala)
appeared in
J. Funct. Anal.
202 (2003) 147--173.
2.
Dirichlet forms, Poincare inequalities, and the Sobolev spaces of
Korevaar-Schoen
(with
Pekka Koskela and
Jeremy Tyson)
appeared in
Potential Analysis. 21 No.3 (2004) 241--262.
3.
A universality property of Sobolev spaces in metric measure spaces
appeared in the Springer collection
Sobolev Spaces in Mathematics I, II, III (2009)
of the
International Mathematical Series.
Last updated 28 September 2009.
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