scholarly journals Hawking radiation in optics and beyond

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190223 ◽  
Author(s):  
Raul Aguero-Santacruz ◽  
David Bermudez
Keyword(s):  
Hawking Radiation ◽  
Dielectric Material ◽  
Numerical Results ◽  
Next Generation ◽  
Hawking Effect ◽  
Physical Systems ◽  
Analogue Gravity ◽  
General Derivation

Hawking radiation was originally proposed in astrophysics, but it has been generalized and extended to other physical systems receiving the name of analogue Hawking radiation. In the last two decades, several attempts have been made to measure it in a laboratory, and one of the most successful systems is in optics. Light interacting in a dielectric material causes an analogue Hawking effect, in fact, its stimulated version has already been detected and the search for the spontaneous signal is currently ongoing. We briefly review the general derivation of Hawking radiation, then we focus on the optical analogue and present some novel numerical results. Finally, we call for a generalization of the term Hawking radiation. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Optical analogues of black-hole horizons

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190232 ◽  
Author(s):  
Yuval Rosenberg
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Refractive Index ◽  
Quantum Mechanics ◽  
Hawking Radiation ◽  
Black Hole Horizon ◽  
Next Generation ◽  
Hands On ◽  
Analogue Gravity ◽  
Classical Fields

Hawking radiation is unlikely to be measured from a real black hole, but can be tested in laboratory analogues. It was predicted as a consequence of quantum mechanics and general relativity, but turned out to be more universal. A refractive index perturbation produces an optical analogue of the black-hole horizon and Hawking radiation that is made of light. We discuss the central and recent experiments of the optical analogue, using hands-on physics. We stress the roles of classical fields, negative frequencies, ‘regular optics’ and dispersion. Opportunities and challenges ahead are briefly mentioned. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Dynamics of flexural gravity waves: from sea ice to Hawking radiation and analogue gravity

2018 ◽  
Vol 474 (2209) ◽  
pp. 20170223 ◽  
Author(s):  
S. Das ◽  
T. Sahoo ◽  
M. H. Meylan
Keyword(s):  
Dispersion Relation ◽  
Sea Ice ◽  
Gravity Waves ◽  
Hawking Radiation ◽  
Compressive Force ◽  
Theory Of Relativity ◽  
Positive Real ◽  
Hawking Effect ◽  
Analogue Gravity ◽  
Flexural Gravity Waves

The propagation of flexural gravity waves, routinely used to model wave interaction with sea ice, is studied, including the effect of compression and current. A number of significant and surprising properties are shown to exist. The occurrence of blocking above a critical value of compression is illustrated. This is analogous to propagation of surface gravity waves in the presence of opposing current and light wave propagation in the curved space–time near a black hole, therefore providing a novel system for studying analogue gravity. Between the blocking and buckling limit of the compressive force, the dispersion relation possesses three positive real roots, contrary to an earlier observation of having a single positive real root. Negative energy waves, in which the phase and group velocity point in opposite directions, are also shown to exist. In the presence of an opposing current and certain critical ranges of compressive force, the second blocking point shifts from the positive to the negative branch of the dispersion relation. Such a shift is known as the Hawking effect from the analogous behaviour in the theory of relativity which leads to Hawking radiation. The theory we develop is illustrated with simulations of linear waves in the time domain.

scholarly journals Computational Performance of Disparate Lattice Boltzmann Scenarios under Unsteady Thermal Convection Flow and Heat Transfer Simulation

Computation ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 65
Author(s):  
Aditya Dewanto Hartono ◽  
Kyuro Sasaki ◽  
Yuichi Sugai ◽  
Ronald Nguele
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Natural Convection ◽  
Lattice Boltzmann ◽  
Numerical Results ◽  
Convection And Heat Transfer ◽  
Steady State Condition ◽  
Physical Systems ◽  
Flow And Heat Transfer ◽  
Computational Performance

The present work highlights the capacity of disparate lattice Boltzmann strategies in simulating natural convection and heat transfer phenomena during the unsteady period of the flow. Within the framework of Bhatnagar-Gross-Krook collision operator, diverse lattice Boltzmann schemes emerged from two different embodiments of discrete Boltzmann expression and three distinct forcing models. Subsequently, computational performance of disparate lattice Boltzmann strategies was tested upon two different thermo-hydrodynamics configurations, namely the natural convection in a differentially-heated cavity and the Rayleigh-Bènard convection. For the purposes of exhibition and validation, the steady-state conditions of both physical systems were compared with the established numerical results from the classical computational techniques. Excellent agreements were observed for both thermo-hydrodynamics cases. Numerical results of both physical systems demonstrate the existence of considerable discrepancy in the computational characteristics of different lattice Boltzmann strategies during the unsteady period of the simulation. The corresponding disparity diminished gradually as the simulation proceeded towards a steady-state condition, where the computational profiles became almost equivalent. Variation in the discrete lattice Boltzmann expressions was identified as the primary factor that engenders the prevailed heterogeneity in the computational behaviour. Meanwhile, the contribution of distinct forcing models to the emergence of such diversity was found to be inconsequential. The findings of the present study contribute to the ventures to alleviate contemporary issues regarding proper selection of lattice Boltzmann schemes in modelling fluid flow and heat transfer phenomena.

Introduction to the Special Issue on Decentralized Blockchain Applications and Infrastructures for Next Generation Cyber-Physical Systems

2021 ◽  
Vol 21 (2) ◽  
pp. 1-3
Author(s):  
Kkwang Raymond Choo ◽  
Uttam Ghosh ◽  
Deepak Tosh ◽  
Reza M. Parizi ◽  
Ali Dehghantanha
Keyword(s):  
Cyber Physical Systems ◽  
Next Generation ◽  
Special Issue ◽  
Physical Systems

Low Temperature Curing - Aqueous Base Developable Photoimageable Dielectric for WLP (Wafer Level Packaging)

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 000986-001015
Author(s):  
Eric Huenger ◽  
Joe Lachowski ◽  
Greg Prokopowicz ◽  
Ray Thibault ◽  
Michael Gallagher ◽  
...  
Keyword(s):  
Low Temperature ◽  
Dielectric Material ◽  
Broad Band ◽  
Dielectric Materials ◽  
Next Generation ◽  
Wafer Level ◽  
Moore’S Law ◽  
Moore's Law ◽  
3D Chip Stacking ◽  
The Impact

As advanced packaging application space evolves and continues to deviate from the conventional shrinkage pathway predicted by Moore's law, material suppliers need to continue to work with OEMs, OSATs and Foundries to identify specific opportunities. One such opportunity continues to present itself in developing new materials to support new platforms for next generation products to support 3D chip stacking and TSV applications. The newer material sets can be established to meet more challenging design requirements associated with the demands, presented by the application from both a physical/lithographical processing and design perspective. Next generation packages requires the development of new dielectric materials that can support both the physical demands of 3D chip stacking and TSV package design aspects while maintaining strengths of the existing material platform. While vertical integration necessitates the use of thinned substrates and its associated integration challenges, there is a continuing need to support horizontal shrinkage typical of the Moore's Law, which pushes the lithography envelope requiring finer pitch and smaller feature resolution capability. This presentation identifies the strategy we have taken and highlights approach taking in the development of low temperature curable photoimageable dielectric materials with enhanced lithographic performance. We will discuss the methodology used to create benzocyclobutene based dielectric material curable at 180 °C and show how lithographic performance can be tuned to allow sub 5 micron via using broad band illumination. Finally we will review the impact of low temperature processing on the mechanical, thermal and electrical properties of this novel photoimageable dielectric material.

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