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How to Untangle Complex Systems?
Published in Pier Luigi Gentili, Untangling Complex Systems, 2018
If the computation to be performed is highly parallelizable or requires many bits of memory, the volume of the computer should be large, and the energy available should be spread out evenly among the different parts of the computer. On the other hand, if the computation is highly serial and requires fewer bits of memory, the energy should be concentrated in a smaller volume. Ideally, the laptop can be compressed up to the black-hole limit (a black-hole of 1 kg has a “Schwarzschild radius” of 1027m). Then, the computation becomes fully serial. A black-hole is suitable for computing because, according to the quantum mechanical picture, it is not entirely black. In fact, a black hole emits the so-called Hawking radiation that contains information about how it has been formed: what goes in does come out but in an altered form.
Miscellaneous Algorithms
Published in Nazmul Siddique, Hojjat Adeli, Nature-Inspired Computing, 2017
Nemati et al. (2013) proposed an extension of BH algorithm by incorporating the charge of the black hole, where the gravitational force of the black hole is used for the global search and the electrical force induced by the charge of the black hole is used for local search. The performance of the proposed algorithm was verified on a set of benchmark problems, which demonstrated better performances over PSO and RBH-PSO. Nemati and Momeni (2014) proposed another extension of BH algorithm by incorporating Hawking's radiation called BH algorithm with fuzzy Hawking radiation. Hawking showed that black holes emit small amounts of thermal radiation (Hawking, 1992), an effect which has become known as Hawking radiation. Hawking radiation is used as a means of mutation mechanism. That is, the individuals went into mutation depending on the fitness value, which is termed as fuzzy Hawking radiation. There was little description provided for the clear understanding of the mechanism of the proposed algorithm, although experimental results based on benchmark problems show improved performance.
Introduction to heat transfer
Published in Tariq Muneer, Jorge Kubie, Thomas Grassie, Heat Transfer, 2012
Tariq Muneer, Jorge Kubie, Thomas Grassie
Based on the principles of quantum mechanics Hawking argued that pairs of particles – pairs of photons and gravitons – continually appear at the event horizon of a black hole. For the purpose of this text, and without indulging into the details of astronomical science, we may loosely consider the event horizon to be the radius at which the escape velocity is the speed of light. Two particles in a pair that start out together may then move apart. After an interval of time they come together and annihilate one another. Some of the pairs will be pairs of matter particles, one of the pair being an antiparticle. Hawking argued that particle pairs appear at the event horizon. However, before the pair meet again and annihilate each other, the one with the negative energy crosses the event horizon into the black hole. The particle with positive energy, now freed of its partnership, may now escape. To an observer at a distance it appears to come out of the black hole and this is known as Hawking radiation.
Hollow vortices of neutrino from Kerr black hole
Published in Waves in Random and Complex Media, 2022
Reyhane Mohamadi Pour, Hassan Sobhani, Hamid Arjomand Kermani
In the quantum theory, the KBHs can emit a thermally distributed radiation spectrum of particles in Hawking radiation [10–16]. So, the energy and the OAM of the RBHs are transferred to the emitted particles and KBHs lose the energy and the OAM in addition to mass due to the particle emission process [17,18]. The exchange of the OAM between two particles in physical phenomena is an interesting subject for researchers [19–21]. One of the particles is the neutrino. Similar to the photon, the neutrino beam acquires OAM when it crosses the gravitational field of KBH [22]. Neutrino emission from an evaporating BH in the spherical coordinate based on parity non-conservation has been investigated [23,24]. Dirac equation for neutrino in the Kerr metric is separated [17,25–27] for an axial symmetric BH [28,29]. However, it is worthy to mention that the Weyl equation which provides a minimal framework for describing the spin of particles, is the simpler equation for massless spin-1/2 particles like the neutrinos [30]. Hawking radiation of neutrino from the cylindrical symmetric BHs, using the Hamilton-Jacobi method has been extended [31] and, a computer program for calculating the Hawking radiation spectra of the KBH has been described recently [32].
Geometric theory of topological defects: methodological developments and new trends
Published in Liquid Crystals Reviews, 2021
Sébastien Fumeron, Bertrand Berche, Fernando Moraes
As can be seen from (9), the effective metric superimposes the background Minkowski metric and a correction taking into account the couplings between field and matter. In the original experiment led by Hippolyte Fizeau, the changes in the velocity field of water (and hence of the Gordon metric itself) were obviously ruled by the Navier-Stokes equations (for the velocity field) instead of Einstein-Cartan equations. In other words, effective spacetimes are generally stationary. Ref [72] pointed out that textures in nematic liquid crystals can indeed be described by the space sector of an Einstein-like equation, with the elastic-stress tensor replacing the energy-momentum tensor. The relevance of the effective metric is therefore restricted to calculations of properties related to the kinematic properties of the fields coupled to matter. This encompasses as we said the geodesics of low-energy excitations but also the less obvious cases of Unruh effect or Hawking radiation which are purely kinematic phenomena [73]. Therefore, the analogy between gravitation and condensed matter is strictly kinematic but not dynamical. To rephrase Wheeler, analog spacetime tells matter how to move…but matter does not tell analog spacetime how to curve.
Black hole entropy, the black hole information paradox, and time travel paradoxes from a new perspective
Published in Journal of Modern Optics, 2020
This issue has also received an enormous amount of attention and been subjected to many sophisticated interpretations (7, 8). If one considers the Hawking radiation as consisting of particles detected at the position of a distant observer, the distribution of these particles is thermal, with a temperature that is consistent with the Bekenstein-Hawking entropy considered above. But the detection of these particles is just like the detection of particles emitted by other quantum systems, from radioactive nuclei (which determine the fate of Schrödinger's cat) to excited atoms undergoing spontaneous emission to the quantum fluctuations in the very early universe which are thought to be responsible for the large scale structures now spread across the sky.