The Condition Order Spectrum

First-Order Condition

0 On Generalizations of the Spectrum Condition

It is well known that the spectrum condition, i.e. the positivity of the energy in every inertial coordinate system, is one of the central conceptual ingedients in model-independent approaches to relativistic quantum field theory. When one attempts to formulate quantum field theory in a model-independent manner on a curved background spacetime, it is not immediately clear which concepts replace...

Passivity and Microlocal Spectrum Condition

In the setting of vector-valued quantum fields obeying a linear wave-equation in a globally hyperbolic, stationary spacetime, it is shown that the two-point functions of passive quantum states (mixtures of groundor KMS-states) fulfill the microlocal spectrum condition (which in the case of the canonically quantized scalar field is equivalent to saying that the two-point function is of Hadamard ...

Order Bi-spectrum For Bearing Fault Monitoring and Diagnosis Under Run-up Condition

Varying speed machinery condition detection and fault diagnosis are more difficult due to non-stationary machine dynamics and vibration. Therefore, most conventional signal processing methods based on time invariant carried out in constant time interval are frequently unable to provide meaningful results. This paper deals with the detection of bearing faults in gearbox under non-stationary run-...

Power Spectrum Condition for Energy-Efficient Watermarking

A simple but powerful theoretical model for watermarking and attacks is presented. The attack consists of Wiener estimation of the watermark, followed by weighted feedback of the estimate to reduce the detector's correlation value. The Wiener attack is provably optimal, and it leads to the notion of energy-e cient watermarking, the generation of watermarks that resist Wiener estimation. It also...