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Related papers: Acoustic metric and Planck constants

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A theory for stabilization of quantum resonances by a mechanism similar to one leading to classical resonances in nonlinear systems is presented. It explains recent surprising experimental results, obtained for cold Cesium atoms when driven…

Chaotic Dynamics · Physics 2009-11-07 Shmuel Fishman , Italo Guarneri , Laura Rebuzzini

We provide a new proof of the equality case of the spacetime positive mass theorem, which states that if a complete asymptotically flat initial data set $(M, g, k)$ satisfying the dominant energy condition has null ADM energy-momentum (that…

Differential Geometry · Mathematics 2023-02-21 Lan-Hsuan Huang , Dan A. Lee

We develop the first steps towards an analysis of geometry on the quantum spacetime proposed in [1]. The homogeneous elements of the universal differential algebra are naturally identified with operators living in tensor powers of Quantum…

High Energy Physics - Theory · Physics 2015-03-17 Dorothea Bahns , Sergio Doplicher , Klaus Fredenhagen , Gherardo Piacitelli

We present a novel space-time isogeometric discretization of the acoustic wave equation in second-order formulation that is intrinsically unconditionally stable. The method relies on a variational framework inspired by [Walkington 2014],…

Numerical Analysis · Mathematics 2025-06-19 Matteo Ferrari , Ilaria Perugia

Inspired by the string axiverse idea, it has been suggested that the recent transition from decelerated to accelerated cosmic expansion is driven by an axion-like quintessence field with a sub-Planckian decay constant. The scenario requires…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-05 Razieh Emami , Daniel Grin , Josef Pradler , Alvise Raccanelli , Marc Kamionkowski

We study space--time isogeometric discretizations of the linear acoustic wave equation that use splines of arbitrary degree p, both in space and time. We propose a space--time variational formulation that is obtained by adding a…

Numerical Analysis · Mathematics 2024-08-02 Sara Fraschini , Gabriele Loli , Andrea Moiola , Giancarlo Sangalli

A critical length has recently been identified that appears to provide a fundamental limit distinguishing quantum behavior from classical behavior. Because of the unique association between critical length and mass, it appears that we can…

General Physics · Physics 2007-05-23 C. L. Herzenberg

The hallmark of quantum physics is Planck's constant $h$, whose finite value entails the quantization that gave the theory its name. The finite value of $h$ gives rise to inevitable zero-point fluctuations even at vanishing temperature. The…

In this paper, we take an in-depth look at the analytical structure of the material transfer functions which govern acoustic and elastic response. These include wavenumber ($\kappa$) in such media and refractive index ($n$), density…

Classical Physics · Physics 2021-11-02 Hossein Khodavirdi , Ankit Srivastava

For any configuration of a static plane-symmetric distribution of matter along space-time, there are coordinates where the metric can be put explicitly as a functional of the energy density and pressures. It satisfies Einstein equations as…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Leandro G. Gomes

Compressible flow varies from ideal-gas behavior at high pressures where molecular interactions become important. Density is described through a cubic equation of state while enthalpy and sound speed are functions of both temperature and…

Fluid Dynamics · Physics 2020-03-11 William A. Sirignano

Both acoustics and electromagnetism represent measurable fields in terms of dynamical potential fields. Electromagnetic force-fields form a spacetime bivector that is represented by a dynamical energy-momentum 4-vector potential field.…

Mathematical Physics · Physics 2024-08-27 Lucas Burns , Tatsuya Daniel , Stephon Alexander , Justin Dressel

We address two problems concerning the ADM mass-minimizing initial data sets. First, we show that the equality case of the positive mass theorem embeds into a pp-wave spacetime. Second, we show that positive Bartnik mass minimizers embed…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Sven Hirsch , Lan-Hsuan Huang

We present a relativistic effective field theory for the interaction between acoustic and gapped phonons in the limit of a small gap. We show that, while the former are the Goldstone modes associated with the spontaneous breaking of…

High Energy Physics - Theory · Physics 2020-11-11 Angelo Esposito , Emma Geoffray , Tom Melia

For the past two years, measurements have been performed with a watt balance at the National Institute of Standards and Technology (NIST) to determine the Planck constant. A detailed analysis of these measurements and their uncertainties…

Celebrated work of Jerrum, Sinclair, and Vigoda has established that the permanent of a {0,1} matrix can be approximated in randomized polynomial time by using a rapidly mixing Markov chain. A separate strand of the literature has pursued…

Computational Complexity · Computer Science 2009-06-10 Cristopher Moore , Alexander Russell

The fundamental constants of electromagnetism, gravity and quantum mechanics can be related empirically by the numerical approximation $\ln(V_e/V_P)\approx \alpha^{-1}$, where $\alpha$ is the low energy value of the electromagnetic fine…

General Physics · Physics 2018-01-31 L. Eaves

We provide a detailed analysis on the acoustic radiation force and torque exerted on a homogeneous viscoelastic particle in the long-wave limit (the particle radius is much smaller than the incident wavelength) by an arbitrary wave. We…

Classical Physics · Physics 2016-04-19 J. P. Leao-Neto , Glauber T. Silva

Based on first- and second-order perturbation theory, we present a numerical study of the temporal build-up and decay of unsteady acoustic fields and acoustic streaming flows actuated by vibrating walls in the transverse cross-sectional…

Fluid Dynamics · Physics 2016-02-02 Peter Barkholt Muller , Henrik Bruus

The enclosed tests demonstrate that an effective pitch can be attributed to acoustic signals shorter then tenths of milliseconds. A power-law dependence of this pitch on the signal's duration time is found for subjects tested with Gaussian…

Classical Physics · Physics 2014-12-16 Marcin Majka , Paweł Sobieszczyk , Robert Gębarowski , Piotr Zieliński