Rotation control of a variable-capacitance electrostatic motor for space equivalence principle tests with rotating masses

The equivalence principle is an important thinking tool to bootstrap our thinking from the inertial coordinate systems of special relativity to the more complex coordinate systems that must be used in the presence of gravity (general relativity). The equivalence principle posits that at a given event gravity accelerates everything equally, so gravity is equivalent to an accelerating coordinate system.This conjecture is well supported by precise experiments, so we explore the consequences in depth: gravity curves the trajectory of light as it does other projectiles; the effects of gravity disappear in a freely falling laboratory; and gravitymakes time runmore slowly in the basement than in the attic—a gravitational form of time dilation. We show how this is observable via gravitational redshift. Subsequent chapters will build on this to show how the spacetime metric varies with location.

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Adaptive Sliding Mode Control Based on Equivalence Principle and Its Application to Chaos Control in a Seven-Dimensional Power System

Mathematical Problems in Engineering ◽

10.1155/2020/1565460 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Jiangbin Wang ◽

Ling Liu ◽

Chongxin Liu ◽

Xiaoteng Li

Keyword(s):

Sliding Mode Control ◽

Power System ◽

Design Process ◽

Equivalence Principle ◽

Sliding Mode ◽

Chaotic Oscillation ◽

Adaptive Sliding Mode Control ◽

Adaptive Sliding Mode ◽

Mode Control ◽

Control Scheme

The main purpose of the paper is to control chaotic oscillation in a complex seven-dimensional power system model. Firstly, in view that there are many assumptions in the design process of existing adaptive controllers, an adaptive sliding mode control scheme is proposed for the controlled system based on equivalence principle by combining fixed-time control and adaptive control with sliding mode control. The prominent advantage of the proposed adaptive sliding mode control scheme lies in that its design process breaks through many existing assumption conditions. Then, chaotic oscillation behavior of a seven-dimensional power system is analyzed by using bifurcation and phase diagrams, and the proposed strategy is adopted to control chaotic oscillation in the power system. Finally, the effectiveness and robustness of the designed adaptive sliding mode chaos controllers are verified by simulation.

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Test of Einstein Equivalence Principle by frequency comparisons of optical clocks

Physics Letters B ◽

10.1016/j.physletb.2021.136471 ◽

2021 ◽

pp. 136471

Author(s):

ChengGang Qin ◽

YuJie Tan ◽

ChengGang Shao

Keyword(s):

Equivalence Principle

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Neutrino oscillation constraints on U(1)′ models: from non-standard interactions to long-range forces

Journal of High Energy Physics ◽

10.1007/jhep01(2021)114 ◽

2021 ◽

Vol 2021 (1) ◽

Author(s):

Pilar Coloma ◽

M. C. Gonzalez-Garcia ◽

Michele Maltoni

Keyword(s):

Contact Interaction ◽

Equivalence Principle ◽

Laboratory Experiments ◽

Global Analysis ◽

Gauge Bosons ◽

Lepton Flavor ◽

Long Baseline ◽

Oscillation Analysis ◽

Weakly Coupled ◽

Effective Contact

Abstract We quantify the effect of gauge bosons from a weakly coupled lepton flavor dependent U(1)′ interaction on the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos in the global analysis of oscillation data. The analysis is performed for interaction lengths ranging from the Sun-Earth distance to effective contact neutrino interactions. We survey ∼ 10000 set of models characterized by the six relevant fermion U(1)′ charges and find that in all cases, constraints on the coupling and mass of the Z′ can be derived. We also find that about 5% of the U(1)′ model charges lead to a viable LMA-D solution but this is only possible in the contact interaction limit. We explicitly quantify the constraints for a variety of models including $$ \mathrm{U}{(1)}_{B-3{L}_e} $$ U 1 B − 3 L e , $$ \mathrm{U}{(1)}_{B-3{L}_{\mu }} $$ U 1 B − 3 L μ , $$ \mathrm{U}{(1)}_{B-3{L}_{\tau }} $$ U 1 B − 3 L τ , $$ \mathrm{U}{(1)}_{B-\frac{3}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 B − 3 2 L μ + L τ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\mu }} $$ U 1 L e − L μ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\tau }} $$ U 1 L e − L τ , $$ \mathrm{U}{(1)}_{L_e-\frac{1}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 L e − 1 2 L μ + L τ . We compare the constraints imposed by our oscillation analysis with the strongest bounds from fifth force searches, violation of equivalence principle as well as bounds from scattering experiments and white dwarf cooling. Our results show that generically, the oscillation analysis improves over the existing bounds from gravity tests for Z′ lighter than ∼ 10−8→ 10−11 eV depending on the specific couplings. In the contact interaction limit, we find that for most models listed above there are values of g′ and MZ′ for which the oscillation analysis provides constraints beyond those imposed by laboratory experiments. Finally we illustrate the range of Z′ and couplings leading to a viable LMA-D solution for two sets of models.

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