Model-independent test of gravity with a network of ground-based gravitational-wave detectors

The observation of gravitational waves with a global network of interferometric detectors such as advanced LIGO, advanced Virgo, and KAGRA will make it possible to probe into the nature of space-time structure. Besides Einstein's general theory of relativity, there are several theories of gravitation that passed experimental tests so far. The gravitational-wave observation provides a new experimental test of alternative theories of gravity because a gravitational wave may have at most six independent modes of polarization whose properties and number of modes are dependent on theories of gravity. This paper develops a method to reconstruct an arbitrary number of modes of polarization in time-series data of an advanced detector network. The method does not rely on any specific model, which gives a model-independent test of alternative theories of gravity.