統計数学セミナー

過去の記録 ~04/25次回の予定今後の予定 04/26~

担当者 吉田朋広、荻原哲平、小池祐太
セミナーURL http://www.sigmath.es.osaka-u.ac.jp/~kamatani/statseminar/
目的 確率統計学およびその関連領域に関する研究発表, 研究紹介を行う.

2017年03月07日(火)

14:00-15:30   数理科学研究科棟(駒場) 052号室
大阪大学基礎工学研究科棟 I407号室 (WEB配信)
Markus Bibinger 氏 (Humboldt-Universität zu Berlin)
Nonparametric change-point analysis of volatility
[ 講演概要 ]
We develop change-point methods for statistics of high-frequency data. The main interest is in the stochastic volatility process of an Itô semi-martingale, the latter being discretely observed over a fixed time horizon. For a local change-point problem under high-frequency asymptotics, we construct a minimax-optimal test to discriminate continuous volatility paths from paths comprising changes. The key example is identification of volatility jumps. We prove weak convergence of the test statistic under the hypothesis to an extreme value distribution. Moreover, we study a different global change-point problem to identify changes in the regularity of the volatility process. In particular, this allows to infer changes in the Hurst parameter of a fractional stochastic volatility process. We establish an asymptotic minimax-optimal test for this problem.