Tilde substitution law in thermo field dynamics: Thermal state conditions

1985 ◽  
Vol 31 (2) ◽  
pp. 429-432 ◽  
Author(s):  
H. Matsumoto ◽  
Y. Nakano ◽  
H. Umezawa
Keyword(s):  
Thermal State ◽  
Thermo Field Dynamics ◽  
Substitution Law

NEW APPLICATION OF THERMO FIELD DYNAMICS IN SIMPLIFYING THE CALCULATION OF WIGNER FUNCTIONS

2003 ◽  
Vol 18 (11) ◽  
pp. 733-742 ◽  
Author(s):  
HONGYI FAN
Keyword(s):  
Matrix Element ◽  
Wigner Function ◽  
Thermal State ◽  
Ensemble Average ◽  
Wigner Functions ◽  
State Representation ◽  
Density Matrices ◽  
Wigner Operator ◽  
Thermo Field Dynamics ◽  
Thermal States

We find that the Thermo Field Dynamics, invented by Takahashi and Umezawa, can simplify calculations of Wigner functions for density matrices ρ. Using the coherent thermal state representation (Phys. Lett.A246, 242 (1998)), we show that the Wigner function W = Tr (Δρ) (an ensemble average of the Wigner operator Δ) can be expressed as a matrix element of ρ in the pure coherent thermal states. Wigner functions for some complicated density matrices are derived in this way.

scholarly journals BLACK HOLES VERSUS FIREWALLS AND THERMO-FIELD DYNAMICS

2013 ◽  
Vol 22 (12) ◽  
pp. 1342011 ◽  
Author(s):  
BORUN D. CHOWDHURY
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Black Hole ◽  
Conformal Field Theory ◽  
Strong Coupling ◽  
Thermal State ◽  
Heat Bath ◽  
De Sitter ◽  
Conformal Field ◽  
Thermo Field Dynamics

In this paper, we examine the implications of the ongoing black holes versus firewalls debate for the thermo-field dynamics of black holes by analyzing a conformal field theory (CFT) in a thermal state in the context of anti-de Sitter/CFT. We argue that the thermo-field doubled copy of the thermal CFT should be thought of not as a fictitious system, but as the image of the CFT in the heat bath. In case of strong coupling between the CFT and the heat bath, this image allows for free infall through the horizon and the system is described by a black hole. Conversely, firewalls are the appropriate dual description in case of weak interaction of the CFT with its heat bath.

CORRELATION INTERACTIONS OF QUANTUM PARTICLES

2019 ◽  
Author(s):  
Evgeniy Krasnopevtsev
Keyword(s):  
Thermal State ◽  
Mutual Interference ◽  
Quantum Gas ◽  
Quantum Particles

Correlation of particles number in an equilibrium thermal state of quantum gas is caused mutual «interference repulsion» and antibunching at fermions and «interference attraction» and bunching at bosons.

Efficiency of special cooling liquid on thermal state of athletes at high temperatures

2019 ◽  
pp. 60-63
Author(s):  
S. M. Rasinkin ◽  
M. V. Dvornikov ◽  
I. A. Artamonova ◽  
V. V. Petrova ◽  
A. A. Kish ◽  
...  
Keyword(s):  
High Temperatures ◽  
Thermal State ◽  
Subjective Evaluation ◽  
Maximal Oxygen Consumption ◽  
Weighted Average ◽  
Male Athletes ◽  
Cooling Liquid ◽  
Sport Teams ◽  
Heat State ◽  
Average Skin

The article presents results of evaluating efficiency of special cooling liquid influence on heat state of athletes at high temperatures. The study covered 7 male athletes of cyclic sports, with sport rank at least 1 adult, average age 19.29±1.80 years. All the athletes underwent double examination including: anamnesis and complaints records, doctor’s examination, subjective evaluation of heat sensations, weight measurements, thermometry (tympanic, sublingual, rectal and skin (in 5 points)), ergospirometric stress testing. Changes in the athletes’ heat state were evaluated via dynamics of weighted average skin temperature and rectal temperature. Moreover, subjective evaluation of heat sensations was considered. Efficiency of the cooling liquid was assessed via dynamics of exercises performance time, maximal oxygen consumption and anaerobic metabolism threshold. The cooling liquid use appeared to be expedientin sport teams of summer sports for specific exertion after individual tests for adverse allergic reactions.

scholarly journals Model-Based Control of Torque and Nitrogen Oxide Emissions in a Euro VI 3.0 L Diesel Engine through Rapid Prototyping

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1107
Author(s):  
Stefano d’Ambrosio ◽  
Roberto Finesso ◽  
Gilles Hardy ◽  
Andrea Manelli ◽  
Alessandro Mancarella ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Rapid Prototyping ◽  
Nitrogen Oxide ◽  
Thermal State ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Nox Emissions ◽  
Model Based ◽  
Brake Mean Effective Pressure ◽  
The Impact

In the present paper, a model-based controller of engine torque and engine-out Nitrogen oxide (NOx) emissions, which was previously developed and tested by means of offline simulations, has been validated on a FPT F1C 3.0 L diesel engine by means of rapid prototyping. With reference to the previous version, a new NOx model has been implemented to improve robustness in terms of NOx prediction. The experimental tests have confirmed the basic functionality of the controller in transient conditions, over different load ramps at fixed engine speeds, over which the average RMSE (Root Mean Square Error) values for the control of NOx emissions were of the order of 55–90 ppm, while the average RMSE values for the control of brake mean effective pressure (BMEP) were of the order of 0.25–0.39 bar. However, the test results also highlighted the need for further improvements, especially concerning the effect of the engine thermal state on the NOx emissions in transient operation. Moreover, several aspects, such as the check of the computational time, the impact of the controller on other pollutant emissions, or on the long-term engine operations, will have to be evaluated in future studies in view of the controller implementation on the engine control unit.

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