High Performance Clocks and Gravity Field Determination

Gravity, Equivalence Principle and Clocks

String theory suggests the existence of gravitational-strength scalar fields (“dilaton” and “moduli”) whose couplings to matter violate the equivalence principle. This provides a new motivation for highprecision clock experiments, as well as a generic theoretical framework for analyzing their significance.

Ers Orbit Determination and Gravity Field Model Tailoring: Recent Developments

In the last ten years significant advances have been made in gravity field modelling, culminating in general-purpose models like JGM-3, TEG-3 and EGM96. Significant defects remain in the quality of the models when applied to orbit determination of some altimeter satellites, leading to large orbit errors, characterised by the geographically-correlated nature of the altimeter crossover height dif...

Global Gravity Field Determination by Combining Goce and Complementary Data

GOCE gravity fields define a new standard concerning spectral resolution of satellite-only models, and provide a very high precision in the longand medium wavelength part of the gravity field up to a spherical harmonic degree of about 250. Combining GOCE with GRACE data, which gives in addition very accurate information for the long wavelength part, results in the current performance status of ...

Investigating High Field Gravity Using Astrophysical Techniques

High Performance Field Emitters

The field electron emission performance of bulk, 1D, and 2D nanomaterials is here empirically compared in the largest metal-analysis of its type. No clear trends are noted between the turn-on electric field and maximum current density as a function of emitter work function, while a more pronounced correlation with the emitters dimensionality is noted. The turn-on field is found to be twice as l...