Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new user4D effective action from non-Abelian DBI action with magnetic flux background
58
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We derive four dimensional $mathcal{N}=1$ supersymmetric effective theory from ten dimensional non-Abelian Dirac-Born-Infeld action compactified on a six dimensional torus with magnetic fluxes on the D-branes. For the ten dimensional action, we use a symmetrized trace prescription and focus on the bosonic part up to $mathcal{O}(F^4)$. In the presence of the supersymmetry, four dimensional chiral fermions can be obtained via index theorem. The matter K{a}hler metric depends on closed string moduli and the fluxes but is independent of flavor, and will be always positive definite if an induced RR charge of the D-branes on which matters are living are positive. We read the superpotential from an F-term scalar quartic interaction derived from the ten dimensional action and the contribution of the matter K{a}hler metric to the scalar potential which we derive turns out to be consistent with the supergravity formulation.
rate research
Read More
We summarize previous results on the most general Proca theory in 4 dimensions containing only first-order derivatives in the vector field (second-order at most in the associated Stuckelberg scalar) and having only three propagating degrees of freedom with dynamics controlled by second-order equations of motion. Discussing the Hessian condition used in previous works, we conjecture that, as in the scalar galileon case, the most complete action contains only a finite number of terms with second-order derivatives of the Stuckelberg field describing the longitudinal mode, which is in agreement with the results of JCAP 1405, 015 (2014) and Phys. Lett. B 757, 405 (2016) and complements those of JCAP 1602, 004 (2016). We also correct and complete the parity violating sector, obtaining an extra term on top of the arbitrary function of the field $A_mu$, the Faraday tensor $F_{mu u}$ and its Hodge dual $tilde{F}_{mu u}$.
Using the background field method for the functional renormalization group approach in the case of a generic gauge theory, we study the background field symmetry and gauge dependence of the background average effective action, when the regulator action depends on external fields. The final result is that the symmetry of the average effective action can be maintained for a wide class of regulator functions, but in all cases the dependence of the gauge fixing remains on-shell. The Yang-Mills theory is considered as the main particular example.
We study $J$-kink domain walls in $D=4$ massive $mathbb{C}P^1$ sigma model. The domain walls are not static but stationary, since they rotate in an internal $S^1$ space with a frequency $omega$ and a momentum ${bf k}$ along the domain wall. They are characterized by a conserved current $J_mu = (Q,{bf J})$, and are classified into magnetic ($J^2 < 0$), null ($J^2=0$), and electric ($J^2 > 0$) types. Under a natural assumption that a low energy effective action of the domain wall is dual to the $D=4$ DBI action for a membrane, we are lead to a coincidence between the $J$-kink domain wall and the membrane with constant magnetic field $B$ and electric field ${bf E}$. We also find that $(Q, {bf J}, omega, {bf k})$ is dual to $(B, {bf E}, H, {bf D})$ with $H$ and ${bf D}$ being a magnetizing field and a displacement field, respectively.
The quantum effective action yields equations of motion and correlation functions including all quantum corrections. We discuss here how it encodes also Noether currents at the full quantum level. This holds both for covariantly conserved currents associated to real symmetries that leave the action invariant as well as for non-conserved Noether currents associated to extended symmetry transformations which change the action, but in a specific way. We discuss then in particular symmetries and extended symmetries associated to space-time geometry for relativistic quantum field theories. These encompass local dilatations or Weyl gauge transformation, local Lorentz transformations and local shear transformations. Together they constitute the symmetry group of the frame bundle GL$(d)$. The corresponding non-conserved Noether currents are the dilatation or Weyl current, the spin current and the shear current for which divergence-type equations of motion are obtained from the quantum effective action.
We show how to calculate the effective potential of SU(3) QCD which tells that the true minimum is given by the monopole condensation. To do this we make the gauge independent Weyl symmetric Abelian decomposition of the SU(3) QCD which decomposes the gluons to the color neutral neurons and the colored chromons. In the perturbative regime this decomposes the Feynman diagram in such a way that the conservation of color is explicit. Moreover, this shows the existence of two gluon jets, the neuron jet and chromon jet, which can be verified by experiment. In the non-perturbative regime, the decomposition puts QCD to the background field formalism and reduces the non-Abelian gauge symmetry to a discrete color reflection symmetry, and provides us an ideal platform to calculate the one-loop effective action of QCD. Integrating out the chromons from the Weyl symmetric Abelian decomposition of QCD gauge invariantly imposing the color reflection invariance, we obtain the SU(3) QCD effective potential which generates the stable monopole condensation and the mass gap. We discuss the physical implications of our result, in particular the possible existence of the vacuum fluctuation mode of the monopole condensation in QCD.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
