Invariant measures for the horocycle flow on periodic hyperbolic surfaces
Invariant measures for the horocycle flow on periodic hyperbolic surfaces
复制标题
周期性双曲曲面上的半圆环流的不变测度
DOI:
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发表时间:
2005
期刊:
影响因子:
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通讯作者:
O. Sarig
中科院分区:
文献类型:
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作者:
F. Ledrappier;O. Sarig
We classify the ergodic invariant Radon measures for the horocycle flow on geometrically infinite regular covers of compact hyperbolic surfaces. The method is to establish a bijection between these measures and the positive minimal eigenfunctions of the Laplacian of the surface. Two consequences arise: if the group of deck transformations G is of polynomial growth, then these measures are classified by the homomorphisms from G0 to ℝ where G0 ≤ G is a nilpotent subgroup of finite index; if the group is of exponential growth, then there may be more than one Radon measure which is invariant under the geodesic flow and the horocycle flow. We also treat regular covers of finite volume surfaces.