Related papers: Real-time geopotentiometry with synchronously link…
Quantum theory and relativity offer different conceptions of time. To explore the conflict between them, we study a quantum version of the light-clock commonly used to illustrate relativistic time dilation. This semiclassical model combines…
Optical clock networks play important roles in various fields, such as precise navigation, redefinition of "second" unit, and gravitational tests. To establish a global-scale optical clock network, it is essential to disseminate time and…
Deployed optical clocks will improve positioning for navigational autonomy, provide remote time standards for geophysical monitoring and distributed coherent sensing, allow time synchronization of remote quantum networks, and provide…
We present a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. The absolute frequency of the clocks can be verified by the use of Er:fiber optical frequency comb with the…
Here within the basic design for a ground-based instrument for measuring the magnitude of the Earth's time-retarded transverse gravitational vector potential is described. The formula for the Earth's transverse vector potential is derived…
Gravitational redshift is an important prediction of General Relativity (GR). We propose a novel dual one-way frequency comparison scheme for gravitational redshift tests in satellite-ground clock experiments. Unlike conventional…
We propose an experimental setup to probe the interplay between the quantum superposition principle and gravitational time dilation arising from the mass-energy equivalence. It capitalizes on state-of-the-art atom interferometers that can…
We report on a reduced time variation of a time scale with respect to Coordinated Universal Time (UTC) by steering a hydrogen-maser-based time scale with a near-continuously operating optical lattice clock. The time scale is generated in a…
The Einstein Equivalence Principle (EEP) is one of the foundations of the theory of General Relativity and several alternative theories of gravitation predict violations of the EEP. Experimental constraints on this fundamental principle of…
We demonstrate a precision frequency measurement using a phase-stabilized 120-km optical fiber link over a physical distance of 50 km. The transition frequency of the 87Sr optical lattice clock at the University of Tokyo is measured to be…
We estimate the sensitivity to nano-Hertz gravitational waves of pulsar timing experiments in which two highly-stable millisecond pulsars are tracked simultaneously with two neighboring radio telescopes that are referenced to the same…
We present a transportable optical clock (TOC) with $^{87}$Sr. Its complete characterization against a stationary lattice clock resulted in a systematic uncertainty of ${7.4 \times 10^{-17}}$ which is currently limited by the statistics of…
The transmission time of an electromagnetic signal in the vicinity of the earth is calculated to c-2 and contains an orbital Sagnac term. On earth, the synchronisation of the Barycentric Coordinate Time (TCB) can be realised by atomic…
Our spacetime is filled with gravitational wave backgrounds that constitute a fluctuating environment created by astrophysical and cosmological sources. Bounds on these backgrounds are obtained from cosmological and astrophysical data but…
Future free-space optical clock networks will require optical links for time and frequency transfer. In many potential realizations of these networks, these links will extend over long distances and will span moving platforms, e.g.…
Assuming the minimal time to send a bit of information in the Einstein clock synchronization of the two clocks located at different positions, we introduce the extended metric to the information space. This modification of relativity…
Atomic clocks have recently reached a fractional timing precision of $<10^{-18}$. We point out that an array of atomic clocks, distributed along the Earth's orbit around the Sun, will have the sensitivity needed to detect the time dilation…
We show that motion and gravity affect the precision of quantum clocks. We consider a localised quantum field as a fundamental model of a quantum clock moving in spacetime and show that its state is modified due to changes in acceleration.…
Optical frequency comparison of the 40Ca+ clock transition \nu_{Ca} (2S1/2-2D5/2, 729nm) against the 87Sr optical lattice clock transition \nu_{Sr}(1S0-3P0, 698nm) has resulted in a frequency ratio \nu_{Ca} / \nu_{Sr} = 0.957 631 202 358…
In this paper we deduce a quite general formula which allows the relation of clock rates at two different space time points to be discussed. In the case of a perturbed Robertson-Walker metric, our analysis leads to an equation for the…