### Conveners

#### Experimental Gravitation: Block 1

- Angela D. V. Di Virgilio (INFN-Pisa)
- Claus Laemmerzahl (University of Bremen)

#### Experimental Gravitation: Block 2

- Angela D. V. Di Virgilio (INFN-Pisa)
- Claus Laemmerzahl (University of Bremen)

### Description

In this session we cover all laboratory experiments testing gravity and the structure of space-time using classical matter, light, and quantum matter. The latter includes atomic clocks, matter wave interferometry, entangled states, etc. We are first dealing with experiments exploring the structure of space-time as it is encoded in the Einstein Equivalence Principle (EEP). This includes tests of the Universality of Free Fall, the Universality of the Gravitational Redshift, and Local Lorentz Invariance, in the classical as well as in the quantum domain. These tests determine the space-time geometry. The next group of tests will explore the field equation of gravity which in most cases is encoded in the PPN formalism; more general formalisms like Finsler geometry, Doubly Special Relativity, etc. also need to be included. The third group of tests deals with testing the predictions of GR. This also will include applications like geodesy, positioning and metrology.

A new type of man-made experiment is precomputed and suggested to enforce the evidence base for general relativity (GR) as the Solar system gravity. We present a detailed analytical and numerical descriptions of a space-probe flight from the Earth towards Venus with Venus’ gravity assist (GA) accelerating the probe to return it to the Earth’s orbit. We demonstrate that any planet’s GA is...

Understanding dark energy and dark matter is one of the most pressing problems in present day physics. In recent years, scalar field models have become popular as candidate theories. As the corresponding hypothetical particles have low masses, collider experiments may not be suitable to search for them. Force metrology at sub-mm scales, on the other hand has proven to be useful in this...

Geometric optics approximation is sufficient to describe the effects in the near-Earth environment. In this framework a careful analysis of the local standard polarization directions allows to obtain transparent expressions for polarization rotation. We provide a simple estimation of this emitter/observer-dependent phase and give its explicit form in different settings: 1) Considering the...

We report on the recent results of testing one of the aspects of Einstein's principle of equivalence - the effect of gravitational redshift, by means of its precision measurement using the Spectr-R as part of the VLBI mission Radioastron.

Satellite Spectr-R and two tracking stations (Green Bank (USA)) and Pushchino (Russia) were equipped with hydrogen frequency standards with relative...

The LISA interferometer, designed for detecting gravitational waves, lends an opportunity to measure the gravitomagnetic field linked by the device. The expected flux is due to the angular momentum of the sun, but could also have a contribution from the angular momentum of the Milky Way, including the dark halo in which our galaxy is likely to be immersed. According to current models, the...

Very slow, so-called ultra-cold neutrons form bound quantum states in the Earth's gravitational field. These neutrons allow the fascinating possibility to investigate gravity at short distances using a simple quantum system. A spectroscopy method for ultra-cold neutrons bound to the surface of mirrors allows to drive transitions between eigen-states of quantum gravitational states. This...

- We consider an inverse procedure as to predict what may be obtained in eLISA , near Earth Orbit, in GW frequency. Among other issues would be the duration of the GW pulse so observed, in eLISA measurements, the relative degree of noise in the signal, as observed by eLISA, and this by the device of a step down in frequency of GW from about 10^19 Hz, in the early universe, or at a minimum...

A method is described for creating a measurable unbalanced gravitational acceleration using a gravitomagnetic field surrounding a superconducting toroid as described by Forward (1962). An experimental Superconducting Magnetic Energy Storage (SMES) toroid configuration of wound superconducting nanowire is proposed to create a measurable acceleration field along the axis of symmetry, providing...

The Newtonian gravity potential is one of the main notions for conventional geodesy and employed for basic concepts, such as the definition of heights. A modern height definition in terms of geopotential numbers can offer a variety of advantages. Moreover, from the theoretical point of view, such a definition is considered more fundamental.

We know, however, that relativistic gravity (here...

Satellite Tests of Relativistic Gravity (SaToR-G) is a new experiment in fundamental physics of the National Scientific Committee 2 (CSN2) of the Italian National Institute for Nuclear Physics (INFN).

The experiment aims at testing gravitation beyond the predictions of Einstein’s Theory of General Relativity in its weak-field and slow-motion limit, searching for effects foreseen by...

G4S_2.0 is a new project funded by the Italian Space Agency (ASI) that aims to perform a set of gravitational measurements with the Galileo satellites of the Full Operational Capability (FOC) constellation. Two of these satellites, GSAT 0201 and GSAT 0202, are characterized by a relatively high eccentricity of their orbits, about 0.16, with respect to that of the other satellites of the...

Ring laser Gyroscopes (RLG) are very versatile devices that find application in many fields as navigation, seismology and geophysics. Moreover, thanks to their sensitivity and accuracy, in the last years they have been used in fundamental physics research field.

GINGER (Gyroscopes IN GEneral Relativity) research group aims to exploit a large RLG to test general relativity theory. Our research...

The debate on gravity theories to extend or modify general relativity is very active today and research efforts are devoted to test theories of gravity. Here, we present the GINGER experiment, which, being Earth based, requires little modeling of external perturbation, allowing a thorough analysis of the systematics, crucial for experiments where sensitivity breakthrough is required.

We...

Gravitational tidal forces conceal very interesting effects when combined with the extended nature of the wavefunction of a freely-falling quantum particle. The reason being that inertial properties of the particle get then mixed with the gravitational effects in such a way that, as in classical mechanics, the ratio of the gravitational mass to the inertial mass of the particle emerges in an...

With the recent direct observation of gravitational waves, a new avenue of observing the Universe has become available. As a result, much effort is being devoted to the design of new detectors sensitive to different gravitational wave sources. One unique proposal is to detect gravitational waves using a Bose-Einstein Condensate (BEC) by using quantum metrology.

In this talk, I will show that...

Note, that micro black holes last within micro seconds, and that we wish to ascertain how to build, in a laboratory, a black hole, which may exist say at least up to 10^−1 seconds and provide a test bed as to early universe gravitational theories. First of all, it would be to determine, if the mini black hole bomb, would spontaneously occur, unless the Kerr-Newmann black hole were carefully...