N = 2 supergravity in the presence of an external magnetic field

1984 ◽  
Vol 62 (1) ◽  
pp. 84-88
Author(s):  
Gerry McKeon

The effective Lagrangian to one-loop order is calculated for N = 2 supergravity in flat space-time in the presence of a constant external magnetic field. The divergences that occur are not renormalizable; this is not unexpected since the background fields do not satisfy the classical equations of motion.

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 146
Author(s):  
Alessandro Coretti ◽  
Lamberto Rondoni ◽  
Sara Bonella

We illustrate how, contrary to common belief, transient Fluctuation Relations (FRs) for systems in constant external magnetic field hold without the inversion of the field. Building on previous work providing generalized time-reversal symmetries for systems in parallel external magnetic and electric fields, we observe that the standard proof of these important nonequilibrium properties can be fully reinstated in the presence of net dissipation. This generalizes recent results for the FRs in orthogonal fields—an interesting but less commonly investigated geometry—and enables direct comparison with existing literature. We also present for the first time a numerical demonstration of the validity of the transient FRs with nonzero magnetic field via nonequilibrium molecular dynamics simulations of a realistic model of liquid NaCl.


2018 ◽  
Vol 32 (10) ◽  
pp. 1850114
Author(s):  
B. Machet

The 1-loop self-energy of a Dirac electron of mass [Formula: see text] propagating in a thin medium simulating graphene in an external magnetic field [Formula: see text] is investigated in quantum field theory. Equivalence is shown with the so-called reduced QED[Formula: see text] on a 2-brane. Schwinger-like methods are used to calculate the self-mass [Formula: see text] of the electron when it lies in the lowest Landau level. Unlike in standard QED[Formula: see text], it does not vanish at the limit [Formula: see text]: [Formula: see text] on-mass-shell renormalization conditions (with [Formula: see text]); all Landau levels of the virtual electron are taken into account and are implemented. Restricting to the sole lowest Landau level of the virtual electron is explicitly shown to be inadequate. Resummations at higher orders lie beyond the scope of this work.


1981 ◽  
Vol 59 (10) ◽  
pp. 1354-1358
Author(s):  
Gerry McKeon

The propagation of a Z meson in a homogeneous magnetic field is studied in the context of the Salam–Weinberg model. One loop corrections to the Z propagator can contain charged virtual particles, leading to an effective interaction with a constant external magnetic field. Only the contribution of virtual charged fermions are considered in this paper.


2012 ◽  
Vol 26 (11) ◽  
pp. 1250086
Author(s):  
JI-ZHOU HE ◽  
XIAN HE ◽  
JIE ZHENG

An entangled quantum refrigerator working with a two-qubit Heisenberg XX model in a constant external magnetic field is constructed in this paper. Based on the quantum first law of thermodynamics, the expressions for several basic thermodynamic quantities such as the heat transferred, the net work and the coefficient of performance are derived. Moreover, the influence of the thermal entanglement on the basic thermodynamic quantities is investigated. Several interesting features of the variation of the basic thermodynamic quantities with the thermal entanglement in zero and nonzero magnetic field are obtained. Lastly, we analyze the maximum coefficient of performance.


1983 ◽  
Vol 29 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Sanjay Kumar Ghosh ◽  
S. P. Pal

The propagation of electromagnetic waves in a plasma-filled cylindrical waveguide in the presence of a constant external magnetic field is investigated using warm plasma theory. It is found that the waves cannot be separated into transverse magnetic and transverse electric modes; only hybrid modes are propagated. Dispersion relations are derived for zero, finite and infinite magnetic fields. Frequency shifts for the wave propagation in the case of a small magnetic field are calculated.


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