Maximal operators and differentiation theorems for sparse sets

We study maximal averages associated with singular measures on \rr. Our main result is a construction of singular Cantor-type measures supported on sets of Hausdorff dimension $1 - \epsilon$, $0 \leq \epsilon < {1/3}$ for which the corresponding maximal operators are bounded on $L^p(\mathbb R)$ for $p > (1 + \epsilon)/(1 - \epsilon)$. As a consequence, we are able to answer a question of Aversa and Preiss on density and differentiation theorems in one dimension. Our proof combines probabilistic techniques with the methods developed in multidimensional Euclidean harmonic analysis, in particular there are strong similarities to Bourgain's proof of the circular maximal theorem in two dimensions. Updates: Andreas Seeger has provided an argument to the effect that our global maximal operators are in fact bounded on L^p(R) for all p>1; in particular, it follows that our differentiation theorems are also valid for all p>1. Furthermore, David Preiss has proved that no such differentiation theorems (let alone maximal estimates) can hold with p=1. These arguments are included in the new version. We have also improved the exposition in a number of places.Comment: Revised version. The final version will appear in Duke Math.

Faktor-faktor yang Mempengaruhi Kualitas Laba pada Perusahaan High Profile yang Terdaftar di Bei

Tujuan penelitian ini adalah untuk mendapatkan bukti empiris mengenai faktor-faktor yang mempengaruhi kualitas laba pada Perusahaan high profile yang terdaftar di Bursa Efek Indonesia (BEI). Kualitas laba diukur dengan menggunakan koefisien respon laba (ERC). Faktor-faktor yang diteliti yaitu persistensi laba, peluang pertumbuhan, risiko, ukuran Perusahaan, kualitas tanggung jawab sosial Perusahaan, kualitas auditor, dan struktur modal. Penelitian ini menggunakan metode purposive sampling dalam pemilihan sampel dari Perusahaan high profile yang terdaftar di BEI periode 2009 sampai 2012. Hasil penelitian menunjukkan bahwa peluang pertumbuhan berpengaruh positif terhadap kualitas laba, sementara risiko, ukuran, dan kualitas tanggung jawab sosial berpengaruh negatif terhadap kualitas laba. Persistensi laba, kualitas auditor, dan struktur modal tidak berpengaruh terhadap kualitas laba

Geometric characteristics of quantum evolution: curvature and torsion

We study characteristics of quantum evolution which can be called curvature and torsion. The curvature shows a deviation of the state vector in quantum evolution from the geodesic line. The torsion shows a deviation of state vector from the plane of evolution (a two-dimensional subspace) at a given time.Comment: 7 pages, 1 figur