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Related papers: Superluminal Signal Velocity

200 papers

We study semi-classical communication in positivity-violating k-essence scalar field theories, with superluminal modes propagating on a rolling background. The self-interactions due to the non-linear nature of these theories pose a…

High Energy Physics - Theory · Physics 2021-10-27 Xi Tong , Yi Wang , Yuhang Zhu

Although information, strictly speaking, is not a physical entity, it generally requires physical entities as its carriers, e.g., writing it down on paper, encoding it with quantum particles, or transmitting it using electro-magnetic…

Quantum Physics · Physics 2026-04-21 Guang Ping He

In this letter we experimentally demonstrate that the signal velocity, defined as the earliest time when a signal is detected above the realistic noise floor, may be altered by a region of anomalous dispersion. We encode information in the…

Quantum Physics · Physics 2012-10-01 Ulrich Vogl , Ryan T. Glasser , Paul D. Lett

Some experiments, performed at Berkeley, Cologne, Florence, Vienna, Orsay, Rennes, etc., led to the claim that something seems to travel with a group velocity larger than the speed c of light in vacuum. Various other experimental results…

Classical Physics · Physics 2016-12-28 Erasmo Recami , Flavio Fontana , Roberto Garavaglia

Recent manifestations of apparently faster-than-light effects confirmed our predictions that the group velocity in transparent optical media can exceed c. Special relativity is not violated by these phenomena. Moreover, in the electronic…

Performance · Computer Science 2015-06-25 Raymond Y. Chiao , Jandir M. Hickmann , Daniel Solli

While particles cannot travel faster than the speed of light, nor can information, this assumption has over the years been frequently questioned. Most recently, it has been argued [New J. Phys. 22, 033038 (2020)] that in a world with…

Quantum Physics · Physics 2026-05-29 Amrapali Sen , Matthias Salzger , Łukasz Rudnicki

Recently, a number of experimental observations on the superluminal group velocities of pulses propagating in dispersive media have led to reconsidering electromagnetism theory in an unconventional framework. To consider faster-than-light…

General Physics · Physics 2023-05-23 Luca Nanni

Solitons in space-time capable of transporting time-like observers at superluminal speeds have long been tied to violations of the weak, strong, and dominant energy conditions of general relativity. This trend was recently broken by a new…

General Relativity and Quantum Cosmology · Physics 2022-01-04 Erik W. Lentz

Theoretical and numerical wave propagation analysis of an oscillating electric dipole is presented. The results show that upon creation at the source, both the longitudinal electric and transverse magnetic fields propagate superluminally…

General Physics · Physics 2007-05-23 William D. Walker

Momentum and spin represent fundamental dynamical properties of quantum particles and fields. In particular, propagating optical waves (photons) carry momentum and longitudinal spin determined by the wave vector and circular polarization,…

Optics · Physics 2014-03-25 Konstantin Y. Bliokh , Aleksandr Y. Bekshaev , Franco Nori

The nonlinear supratransmission is the property of a nonlinear system possessing a natural forbidden band gap to transmit energy of a signal with a frequency in the gap by means of generation of nonlinear modes (gap solitons). This process…

Pattern Formation and Solitons · Physics 2015-06-26 J. Leon

The purpose of this paper is to present mathematical evidence that electromagnetic near-field waves and wave groups, generated by an oscillating electric dipole, propagate much faster than the speed of light as they are generated near the…

General Physics · Physics 2007-05-23 William D. Walker

Contemporary observational and theoretical studies on the temporal nature of microscopic measurements renewed the discussion about the fundamental constants, leading to the possibility of light speed variation and superluminal pulse…

General Physics · Physics 2007-05-23 R Assumpcao

This paper shows that ordinary quantum mechanics is not consistent with the superluminal transmission of classical information.

Quantum Physics · Physics 2007-05-23 Michael D. Westmoreland , Benjamin Schumacher

Modern precision experiments often probe unknown classical fields with bosonic sensors in quantum-noise-limited regimes where vacuum fluctuations limit conventional readout. We introduce Quantum Signal Learning (QSL), a sensing framework…

Quantum Physics · Physics 2026-02-24 Jordan Cotler , Daine L. Danielson , Ishaan Kannan

A simple experiment is presented which indicates that electromagnetic fields propagate superluminally in the near-field next to an oscillating electric dipole source. A high frequency 437MHz, 2 watt sinusoidal electrical signal is…

General Physics · Physics 2007-05-23 William D. Walker

Any charged particle moving faster than light through a medium emits Cherenkov radiation. We show that charged particles moving faster than light through the v a c u u m emit Cherenkov radiation. How can a particle move faster than light?…

Quantum Physics · Physics 2009-11-07 Daniel Rohrlich , Yakir Aharonov

We discuss the properties of the transmission function in the k-space for a generic multi-layered structure. In particular we analytically demonstrate that a transmission greater than one in the evanescent spectrum (amplification of the…

The causal properties of curved spacetime, which underpin our sense of time in gravitational theories, are defined by the null cones of the spacetime metric. In classical general relativity, it is assumed that these coincide with the light…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. M. Shore

There is suggested a version of the experiment with a correlated pair of particles in the entangled state. The experiment demonstrates that, in the case of weak and/or non-demolition measurements of one of the particles, it is possible to…

General Physics · Physics 2016-12-21 A. V. Belinsky , A. K. Zhukovsky