Removing resonance effects from quantum mechanical vibrational partition functions obtained from perturbation theory

1998 ◽  
Vol 108 (24) ◽  
pp. 9978-9986 ◽  
Author(s):  
Alan D. Isaacson
Keyword(s):  
Perturbation Theory ◽  
Quantum Mechanical ◽  
Partition Functions ◽  
Resonance Effects

scholarly journals One-loop non-planar anomalous dimensions in super Yang-Mills theory

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Tristan McLoughlin ◽  
Raul Pereira ◽  
Anne Spiering
Keyword(s):  
Perturbation Theory ◽  
Integrable Systems ◽  
Chaotic Systems ◽  
Quantum Mechanical ◽  
Matrix Elements ◽  
Mechanical Perturbation ◽  
Yang Mills ◽  
Anomalous Dimensions ◽  
Dilatation Operator ◽  
Scalar Products

Abstract We consider non-planar one-loop anomalous dimensions in maximally supersymmetric Yang-Mills theory and its marginally deformed analogues. Using the basis of Bethe states, we compute matrix elements of the dilatation operator and find compact expressions in terms of off-shell scalar products and hexagon-like functions. We then use non-degenerate quantum-mechanical perturbation theory to compute the leading 1/N2 corrections to operator dimensions and as an example compute the large R-charge limit for two-excitation states through subleading order in the R-charge. Finally, we numerically study the distribution of level spacings for these theories and show that they transition from the Poisson distribution for integrable systems at infinite N to the GOE Wigner-Dyson distribution for quantum chaotic systems at finite N.

Multiphoton Ionization

1991 ◽  
Vol 02 (01) ◽  
pp. 387-390
Author(s):  
ERNA KARULE
Keyword(s):  
Perturbation Theory ◽  
Atomic Hydrogen ◽  
Multiphoton Ionization ◽  
Quantum Mechanical Calculation ◽  
Quantum Mechanical ◽  
Mechanical Calculation ◽  
Above Threshold Ionization ◽  
Strong Laser Fields ◽  
Intense Light ◽  
Intense Light Beam

Multiphoton ionization happens in an intense light beam when atoms absorb more than one photon. In strong fields an atom may absorb not only the minimum energetically necessary number of photons for ionization, but also excess photons. The last process is the so called “above threshold ionization” (ATI) which as well as “normal” multiphoton ionization (MPI) takes place in the strong laser fields. Both processes are between those responsible for the energy transfer from the laser to the plasma. The paper deals with the quantum mechanical calculation of MPI and ATI of atomic hydrogen. At the moderate intensities of light these processes may be treated by methods of perturbation theory.

scholarly journals Quantum-mechanical Rotational and Vibrational Signatures of Astrophyscially relevant Gas-Phase Stereo-isomeric Species of Leucine

2020 ◽  
Author(s):  
Namrata Rani ◽  
. Vikas
Keyword(s):  
Perturbation Theory ◽  
Amino Acid ◽  
Interstellar Medium ◽  
Gas Phase ◽  
Spectroscopic Data ◽  
Outer Space ◽  
Quantum Mechanical ◽  
Complex Chemical ◽  
Quantum Mechanical Computations ◽  
Second Order Perturbation Theory

The search for life-supporting molecules in outer space is an ever growing endeavour. Towards this, the quantum-mechanical computations supporting the astronomical spectroscopic observations are becoming valuable tools to unravel the complex chemical network in the interstellar medium (ISM). In the present work, quantum-mechanical computations are performed to obtain the rotational and vibrational line-data of gas-phase conformers of amino acid Leucine and its isomeric species predicted to be involved in its stereoinversion under the conditions of ISM. These species exhibit diverse chemistry including branched skeleton and zwitterionic ammonium ylides. Notably, the present work employs vibrational second order perturbation theory to account for anharmonic effects in rotational and vibrational transitions. The spectroscopic data computed in this work can assist in the detection of Leucine and its isomeric species in different regions of ISM.

Sign in / Sign up

Export Citation Format

Share Document