scholarly journals Generalized gravitational entropy from total derivative action

2015 ◽  
Vol 2015 (12) ◽  
pp. 1-22 ◽  
Author(s):  
Xi Dong ◽  
Rong-Xin Miao
Keyword(s):  
Total Derivative ◽  
Gravitational Entropy

The cooperation between loop quantum gravity and Entropic gravity

2021 ◽  
Author(s):  
Wen-Xiang Chen
Keyword(s):  
Boundary Condition ◽  
Quantum Gravity ◽  
Gravitational Potential ◽  
Complex Number ◽  
Loop Quantum Gravity ◽  
Gravitational Entropy ◽  
Entropic Gravity ◽  
New Form

In this paper, we show that bosons can produce bochromatic condensation without an energy layer when the boundary condition $\frac{T}{T_{c}}=z$(when z is complex) is preset. $r_{R}=zr_{A}\left(1-\frac{v^{2}}{c^{2}}\right)^{\frac{1}{2}}$(when z is A complex number). A new form of gravitational potential is obtained by combining the theory of gravitational entropy with loop quantum gravity.

scholarly journals Gravitational entropy of cosmic expansion

2014 ◽  
Vol 335 (6-7) ◽  
pp. 587-592 ◽  
Author(s):  
R. A. Sussman
Keyword(s):  
Cosmic Expansion ◽  
Gravitational Entropy

On perturbation range in the feedback synthesis problem for a chain of integrators system

2020 ◽  
Author(s):  
V I Korobov ◽  
T V Revina
Keyword(s):  
Finite Time ◽  
Initial Point ◽  
Settling Time ◽  
Time Function ◽  
Synthesis Problem ◽  
Total Derivative ◽  
Perturbed System ◽  
Arbitrary Initial Point ◽  
Feedback Synthesis ◽  
A Chain

Abstract The feedback synthesis problem for a chain of integrators system with continuous bounded unknown perturbation is considered. Our approach is based on the controllability function (CF) method proposed by V.I. Korobov. The perturbation range is determined by the negativity condition for the total derivative of the CF with respect to the perturbed system. The control that does not depend on perturbation under some restrictions and steers an arbitrary initial point from a neighborhood of the origin to the origin in a finite time (settling-time function) is constructed. The settling-time function depends on the perturbation, but it remains bounded from below and from above by the same value.

A Mathematical Model for Predicting Conditions That Prevent Gaseous Fuel-Air Mixing

2000 ◽  
Author(s):  
Dan Brasoveanu ◽  
Ashwani K. Gupta
Keyword(s):  
Chemical Species ◽  
Combustion Products ◽  
Gaseous Fuel ◽  
Total Derivative ◽  
Operational Conditions ◽  
Gaseous Fuels ◽  
Air Mixing ◽  
Pollutants Emission ◽  
Single Chemical ◽  
Fuel Mass Fraction

Abstract A unified model is used here to determine the distributions of pressure, temperature and velocity that reduce gaseous fuel-air mixing. The model uses the fuel mass fraction within infinitesimal fluid elements and the total derivative of this fraction with respect to time to quantify the degree and rate of mixing, respectively. An Eulerian representation is used. The model is valid for gaseous fuels that contain a single chemical species and for low-pressure combustors. The model permits the presence of only trace amounts of combustion products within the mixing region. Aside from these restrictions, the mixing model can be applied to a variety of combustor designs and operational conditions. Results show that certain distributions of pressure, temperature and velocity at the fuel-air boundary reduce or even prevent gaseous fuel-air mixing, in particular whenever the logarithmic rate of temperature and the velocity divergence are comparable. These conditions yield low intensity and efficiency combustion as well as high pollutants emission level.

scholarly journals A NEW SPIN ON QUANTUM GRAVITY

2008 ◽  
Vol 17 (03n04) ◽  
pp. 567-570 ◽  
Author(s):  
MARK G. JACKSON ◽  
CRAIG J. HOGAN
Keyword(s):  
Quantum Gravity ◽  
Cosmological Constant ◽  
Laboratory Tests ◽  
Space Time ◽  
Quantum Spin ◽  
Inherent Property ◽  
Fundamental Level ◽  
Bose Statistics ◽  
Gravitational Entropy

We suggest that the (small but nonvanishing) cosmological constant, and the holographic properties of gravitational entropy, may both reflect unconventional quantum spin statistics at a fundamental level. This conjecture is motivated by the nonlocality of quantum gravity and the fact that spin is an inherent property of space–time. As an illustration we consider the "quon" model, which interpolates between Fermi and Bose statistics, and show that this can naturally lead to an arbitrarily small cosmological constant. In addition to laboratory tests, we briefly discuss the possible observable imprint on cosmological fluctuations from inflation.

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