scholarly journals A REMARK ON NONCONFORMAL NONSUPERSYMMETRIC THEORIES WITH VANISHING VACUUM ENERGY DENSITY

2001 ◽  
Vol 16 (27) ◽  
pp. 1761-1773
Author(s):  
OLINDO CORRADINI ◽  
ALBERTO IGLESIAS ◽  
ZURAB KAKUSHADZE ◽  
PETER LANGFELDER
Keyword(s):  
Field Theory ◽  
Perturbation Theory ◽  
Energy Density ◽  
Vacuum Energy ◽  
Gauge Theories ◽  
Vacuum Energy Density ◽  
Large N

We discuss nonconformal nonsupersymmetric large-N gauge theories with vanishing vacuum energy density to all orders in perturbation theory. These gauge theories can be obtained via a field theory limit of type IIB D3-branes embedded in orbifolded space–times. We also discuss gravity in this setup.

scholarly journals DIAGRAMMATIC APPROACH TO THE VACUUM ENERGY DENSITY: THE GROSS-NEVEU MODEL AT LARGE-N

1994 ◽  
Vol 09 (13) ◽  
pp. 1195-1205 ◽  
Author(s):  
HIROFUMI YAMADA
Keyword(s):  
Energy Density ◽  
Effective Charge ◽  
Vacuum Energy ◽  
Chiral Condensate ◽  
Vacuum Energy Density ◽  
Hartree Fock ◽  
Large N ◽  
Optimal Value ◽  
Exact Energy ◽  
Gross Neveu Model

An approach to the vacuum energy density based on a direct diagrammatic expansion in the generalized Hartree-Fock scheme is studied in the Gross-Neveu model as an example. To keep the coherence with the calculation of the chiral condensate, the vacuum energy density, ε, is expanded in terms of the effective charge associated with the condensate. Then ε is calculated by substituting the optimal value of the effective charge which specifies the solution for the condensate. The result agrees well with the exact energy density to several higher orders of the expansion, showing that our procedure works well.

scholarly journals LOCAL CONTRIBUTION OF A QUANTUM CONDENSATE TO THE VACUUM ENERGY DENSITY

2003 ◽  
Vol 18 (10) ◽  
pp. 683-690 ◽  
Author(s):  
GIOVANNI MODANESE
Keyword(s):  
Energy Density ◽  
Vacuum Energy ◽  
Casimir Effect ◽  
Landau Equation ◽  
Vacuum Energy Density ◽  
Negative Effects ◽  
Ginzburg Landau ◽  
Physical Conditions ◽  
Local Contribution ◽  
Gravitational Vacuum

We evaluate the local contribution gμνL of coherent matter with Lagrangian density L to the vacuum energy density. Focusing on the case of superconductors obeying the Ginzburg–Landau equation, we express the relativistic invariant density L in terms of low-energy quantities containing the pairs density. We discuss under which physical conditions the sign of the local contribution of the collective wave function to the vacuum energy density is positive or negative. Effects of this kind can play an important role in bringing the local changes in the amplitude of gravitational vacuum fluctuations — a phenomenon reminiscent of the Casimir effect in QED.

scholarly journals Brownian motion and polarized three-dimensional quantum vacuum

2021 ◽  
Vol 67 (4 Jul-Aug) ◽  
Author(s):  
Davide Fiscaletti
Keyword(s):  
Dark Matter ◽  
Brownian Motion ◽  
Energy Density ◽  
Nonlinear Model ◽  
Vacuum Energy ◽  
Three Dimensional ◽  
Vacuum Energy Density ◽  
Quantum Vacuum ◽  
Virtual Particles ◽  
Fundamental Entity

A nonlinear model of Brownian motion is developed in a three-dimensional quantum vacuum defined by a variable quantum vacuum energy density corresponding to processes of creation/annihilation of virtual particles. In this model, the polarization of the quantum vacuum determined by a perturbative fluctuation of the quantum vacuum energy density associated with a fluctuating viscosity, which mimics the action of dark matter, emerges as the fundamental entity which generates the Brownian motion.

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