Tutorial on Additive Levy´ ProcessesLecture #2Davar KhoshnevisanDepartment of MathematicsUniversity of Utahhttp://www.math.utah.edu/˜davarInternational Conference on Stochastic Analysisand Its ApplicationsAugust 7–11, 2006D. Khoshnevisan (Salt Lake City, Utah) ICSAA, Seattle ’06 1 / 23åDefinition (Hausdorff, 1919)The s dimensional Hausdorff measure ofA iss sH (A) := limH (A).↓0Spherical measure (Besicovitch)Hausdorff Measure and DimensiondIf A∈ R and s > 0 then( )∞∞ [s sH (A) := inf (2r ) : A B(x , r ), 0 r .n n n nn=1 n=1D. Khoshnevisan (Salt Lake City, Utah) ICSAA, Seattle ’06 2 / 23åHausdorff Measure and DimensiondIf A∈ R and s > 0 then( )∞∞ [s sH (A) := inf (2r ) : A B(x , r ), 0 r .n n n nn=1 n=1Definition (Hausdorff, 1919)The s dimensional Hausdorff measure ofA iss sH (A) := limH (A).↓0Spherical measure (Besicovitch)D. Khoshnevisan (Salt Lake City, Utah) ICSAA, Seattle ’06 2 / 23Definition (“Hausdorff Dimension”; Hausdorff, 1919)s sdim A = sup{s : H (A) =∞} = inf{s > 0 : H (A) = 0}.HHausdorff Measure and DimensionTheorem (Hausdorff, 1919)s dFor all s > 0, the restriction of H to Borel sets in R is a measure.D. Khoshnevisan (Salt Lake City, Utah) ICSAA, Seattle ’06 3 / 23Hausdorff Measure and DimensionTheorem (Hausdorff, 1919)s dFor all s > 0, the restriction of H to Borel sets in R is a measure.Definition (“Hausdorff Dimension”; Hausdorff, 1919)s sdim A = sup{s : H (A) =∞} = inf{s > 0 : H (A) = 0}.HD. ...
Voir