Generalizing results by Bryant and Griffiths [Duke Math. J., 1995, V.78, 531–676], we completely describe local conservation laws of second-order (1 + 1)-dimensional evolution equations up to contact equivalence. The possible dimensions of spaces of conservation laws prove to be 0, 1, 2 and infinity. The canonical forms of equations with respect to contact equivalence are found for all nonzero ...

The classical aggregation result by Tiao (1972, Asymptotic Behavior of Temporal Aggregates of Time Series, Biometrika 59, 525-531) is generalized for a weak set of assumptions. The innovations driving the integrated processes are only required to be stationary with integrable spectral density. The derivation is settled in the frequency domain. In case of fractional integration it is demonstrate...

Bibliographie: Wegner, Lukas: Stefan Thomas: Ethnografie. Eine Einführung. Wiesbaden: Springer VS 2019, 169 S., 978-3-531-94218-6. 17,99 €., ZQF – Zeitschrift für Qualitative Forschung, 2-2021, S. 331-334. https://doi.org/10.3224/zqf.v22i2.10 ----- Open-Access-Lizenz: Dieser Beitrag ist ab dem 18.02.2022 im Open Access unter der Creative-Commons-Lizenz CC BY 4.0 (Namensnennung International) ve...