Status of the GINGER project

Large frame ring laser gyroscopes, based on the Sagnac effect, are top sensitivity instrumentation to measure angular velocity with respect to
the fixed stars. GINGER (Gyroscopes IN GEneral Relativity) project foresees the construction of an array of three large dimension ring laser
gyroscopes, rigidly connected to the Earth. GINGER has the potentiality to measure general relativity effects and Lorentz Violation in the
gravity sector, once a sensitivity of 10 9, or better, of the Earth rotation rate is obtained. Being attached to the Earth crust, the array will also
provide useful data for geophysical investigation. For this purpose, it is at present under construction as part of the multi-components observatory
called Underground Geophysics at Gran Sasso (UGSS). Sensitivity is the key point to determine the relevance of this instrument for
fundamental science. The most recent progress in the sensitivity measurement, obtained on a ring laser prototype called GINGERINO, indicates
that GINGER should reach the level of 1 part in 1011 of the Earth rotation rate.