scholarly journals Holographic chaos, pole-skipping, and regularity

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Makoto Natsuume ◽  
Takashi Okamura
Keyword(s):  
Field Equation ◽  
Energy Density ◽  
Green's Function ◽  
Special Point ◽  
Curvature Singularity ◽  
Curvature Invariants ◽  
Momentum Plane ◽  
The Future ◽  
Outgoing Mode ◽  
Future Horizon

Abstract We investigate the “pole-skipping” phenomenon in holographic chaos. According to pole-skipping, the energy-density Green’s function is not unique at a special point in the complex momentum plane. This arises because the bulk field equation has two regular near-horizon solutions at the special point. We study the regularity of the two solutions more carefully using curvature invariants. In the upper-half $\omega$-plane, one solution, which is normally interpreted as the outgoing mode, is in general singular at the future horizon and produces a curvature singularity. However, at the special point, both solutions are indeed regular. Moreover, the incoming mode cannot be uniquely defined at the special point due to these solutions.

scholarly journals A new result under weak and non-relativistic approximation from general theory of relativity

2021 ◽  
Author(s):  
Abhijit Samanta
Keyword(s):  
Field Equation ◽  
Energy Density ◽  
General Theory ◽  
Force Field ◽  
Coordinate System ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Inertial Coordinate System ◽  
Relativistic Approximation ◽  
Moving Particle

Abstract We have derived a metric field equation in the locally inertial coordinate system from Einstein's field equation considering the energy density of the moving particle with the approximations that the force field under which the particle is moving is weak and the velocity of the particle is non-relativistic. We study the motion of different microscopic systems using this metric equation and compared the results with the experimentally measured values and we find that the results are identical.

Future Trend Analysis on the Design and Performance of Solar-Powered Electric Unmanned Aerial Vehicles

2015 ◽  
Vol 1125 ◽  
pp. 635-640 ◽  
Author(s):  
Parvathy Rajendran ◽  
Howard Smith
Keyword(s):  
Energy Density ◽  
Weight Ratio ◽  
Future Trend ◽  
Solar Module ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
The Future ◽  
Solar Powered ◽  
Battery Technology ◽  
Battery Energy

This paper analyzes the future trends of both solar and non-solar-powered electric types of unmanned aerial vehicle (UAV). The impacts of solar cell efficiency and battery energy density on the potential of reducing the maximum take-off and payload enhancement for both types of UAV are studied. The battery energy density and solar efficiency’s extrapolated forecast data do not show any sign of technology maturation. Component weight, ratio of solar module to wing area, and solar module power are also analyzed to further emphasize the need to improve the solar and battery technology for the development of solar-powered electric UAVs. Results show that a solar-powered electric UAV should be lighter, smaller, and be able to carry more payload than a non-solar-powered electric UAV in the near future depending on the payload and endurance requirement. Thus, a solar-powered aircraft can be the future of aviation.

scholarly journals Hermann Cohen w drodze ku „Religii rozumu ze źródeł judaizmu”. Przystanek Breslau

2019 ◽  
Vol 14 (3) ◽  
pp. 21-35
Author(s):  
Ryszard Różanowski
Keyword(s):  
Academic Career ◽  
Educational Institution ◽  
Special Point ◽  
Theological Seminary ◽  
The Future ◽  
Religion Of Reason ◽  
The University ◽  
The 19Th Century ◽  
Hermann Cohen ◽  
The Way

Hermann Cohen on the Way to „Religion of Reason: Out of the Sources of Judaism” Breslau Stop On the way leading Hermann Cohen from his family Coswig to Marburg and — later — to Berlin, from a Jewish province to a multicultural metropolis, Breslau is a special point. The future philosopher came here in 1857, hoping for the future of fice of the rabbi, to begin studies at the newly established Jewish Theological Seminary. Here too, four years later, he enrolled at the university, opening up the prospect of an academic career. A special point, which allowed him to create in the next years an “impressive system” which is a bold attempt to present German and Judaism as identical or connected. Jewish and religious content was a permanent and constant component of Cohen’s works, and Religion of Reason and System of Philosophy form a whole. Already before the creation of works devoted to Kant, some features of Cohen’s philosophy of religion are revealed, which originated in his studies at Breslau, one of the most important Haskalah centers in the middle of the 19th century. Cohen found there an atmosphere conduciveto the later shaping of the science of the universal religion of reason. After many years, Cohen assessed the Jewish Theological Seminary as “the most important educational institution [of his] youth.”

scholarly journals Quantum Cosmology vs. Observational Cosmology (A Simple, Curious and Advanced Approach)

2016 ◽  
Author(s):  
U. V. S. Seshavatharam ◽  
S. Lakshminarayana
Keyword(s):  
Energy Density ◽  
Kinetic Energy ◽  
Hubble Parameter ◽  
Quantum Cosmology ◽  
Mass Density ◽  
Critical Density ◽  
Observational Cosmology ◽  
Cosmic Expansion ◽  
Expansion Speed ◽  
The Future

With reference to Planck scale Hubble parameter, super luminal expansion speeds, super luminal rotation speeds and Mach’s principle, we review the current cosmological observations. With our revised assumptions, it is possible to show that, at H0 =70 km/sec/Mpc, current cosmic temperature, age, radius, mass, mass density and rotational kinetic energy are 2.721 K, 4.41 x 1017 sec, 90 billion light years, 1.14654 x 1054 kg, 0.0482 times the current critical density and 0.6667 times the current critical energy density respectively. Based on the estimated current mass density and current rotational kinetic energy density, current cosmic dark matter density can be shown to be 0.2851 times the current critical density. Initial and current expansion speeds are 3 x 108 m/sec and 3.56 x 109 m/sec respectively. Proceeding further, we developed two interesting methods for understanding cosmic scale factor with reference to a temperature of 3000 K, redshift of 1100 and age of 3,69,000 years. Finally we would like to suggest that, with increasing cosmic age and increasing cosmic expansion speed, current universe is expanding with a speed of 11.885c. Magnitude of the future cosmic expansion speed depends on the magnitude of the future Hubble parameter. By knowing the time to time future cosmic temperatures, corresponding future Hubble parameters can be estimated and corresponding future cosmic expansion speeds can also be estimated.Proceeding further, a unified model of evolving quantum cosmology can be developed.

scholarly journals Riding gravity away from doomsday

2015 ◽  
Vol 24 (12) ◽  
pp. 1544004 ◽  
Author(s):  
Ashoke Sen
Keyword(s):  
Phase Transition ◽  
Quantum Theory ◽  
Dark Energy ◽  
Energy Density ◽  
The Future ◽  
Theory Of Gravity ◽  
The Universe

The discovery that most of the energy density in the universe is stored in the form of dark energy has profound consequences for our future. In particular, our current limited understanding of quantum theory of gravity indicates that some time in the future, our universe will undergo a phase transition that will destroy us and everything else around us instantaneously. However, the laws of gravity also suggest a way out — some of our descendants could survive this catastrophe by riding gravity away from the danger. This paper describes the tale of this escape from doomsday.

An improved theory of gravitation. Part I

1968 ◽  
Vol 46 (19) ◽  
pp. 2155-2179 ◽  
Author(s):  
Peter Rastall
Keyword(s):  
Field Equation ◽  
Energy Density ◽  
Special Relativity ◽  
Gravitational Potential ◽  
Functional Dependence ◽  
Gravitational Interaction ◽  
Gravitational Energy ◽  
Additive Constant ◽  
Newtonian Theory ◽  
Theory Of Gravitation

A theory of gravitation is developed from assumptions that differ as little as possible from those of special relativity and the Newtonian theory of gravitation. As in special relativity, one assumes the existence of preferred coordinate systems (Newtonian charts) in which the nondiagonal components of the metric vanish, and in which the spatial, diagonal components are equal. The metric is determined by a single real function, the gravitational potential, which is assumed, as in the Newtonian theory, to be arbitrary to the extent of an additive constant. A uniqueness theorem is proved for Newtonian charts, and the functional dependence of the metric on the gravitational potential is determined (apart from two constants, which are later fixed by requiring that the equations of motion of a particle have the correct, nonrelativistic limit, and that the potential due to a fixed particle have the Newtonian form at great distances). By a simple change in the units of space and time, the geometry is made Minkowskian. A similar change in the units of mass makes the theory formally similar to special relativity. Particle dynamics is developed. The red shift and the deflection of light by a star are calculated, and agree with the Einstein results. The combination of the assumptions that the potentials due to particles are additive and that the potential due to a fixed particle is not proportional to 1/r, is shown to lead to difficulties. The weight of a simple system is found to be proportional to its total energy, including its gravitational interaction energy. Continuous, static mass distributions are considered. A field equation is derived for the static gravitational potential, and an expression for the energy density of the static gravitational field. The field equation is modified by assuming that the gravitational energy density is itself a source of the gravitational potential. The potential due to a static, spherically symmetric body is calculated, and the perihelion advance of a planet is found to be 11/12 of the Einstein value, in good agreement with the results of Dicke.

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