scholarly journals Holographic Schwinger effect with a deformed AdS background

2017 ◽  
Vol 32 (10) ◽  
pp. 1750045 ◽  
Author(s):  
J. Sadeghi ◽  
B. Pourhassan ◽  
S. Tahery ◽  
F. Razavi

In this paper, we consider a deformed AdS background and study the effect of deformation parameter on the pair production rate of the Schwinger effect. The electrostatic potential is important for the pair production in the holographic Schwinger effect. In this paper, we analyze the electrostatic potential in a deformed AdS background and investigate the effect of deformation parameter which may be useful to test the AdS/QCD. In the case of zero temperature, we find that the larger value of the deformation parameter leads to a smaller value of separation length of the test particles on the probe. Also, we find a finite maximum of separation length in the presence of modification parameter.

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Udit Narayan Chowdhury

We consider the phenomenon of spontaneous pair production in the presence of an external electric field for noncommutative Yang-Mills theories. Using Maldacena’s holographic conjecture, the threshold electric field for pair production is computed from the quark/antiquark potential for noncommutative theories. As an effect of noncommutativity, the threshold electric field is seen to be smaller than its commutative counterpart. We also estimate the correction to the production rate of quark/antiquark pairs to the first order of the noncommutative deformation parameter. Our result bears resemblance with an earlier related work (based on field-theoretic methods).


2018 ◽  
Vol 33 (25) ◽  
pp. 1850144
Author(s):  
Maryam Gholizadeh Arashti ◽  
Majid Dehghani

The Schwinger effect in the presence of instantons and background magnetic field was considered to study the dependence of critical electric field on instanton density and magnetic field using AdS/CFT conjecture. The gravity side is the near horizon limit of D3[Formula: see text]D(−[Formula: see text]1) background with electric and magnetic fields on the brane. Our approach is based on the potential analysis for particle–antiparticle pair at zero and finite temperatures, where the zero temperature case is a semi-confining theory. We find that presence of instantons suppresses the pair creation effect, similar to a background magnetic field. Then, the production rate will be obtained numerically using the expectation value of circular Wilson loop. The obtained production rate in a magnetic field is in agreement with previous results.


2015 ◽  
Vol 30 (11) ◽  
pp. 1530026 ◽  
Author(s):  
Daisuke Kawai ◽  
Yoshiki Sato ◽  
Kentaroh Yoshida

This is a review of the recent progress on a holographic description of the Schwinger effect. In 2011, Semenoff and Zarembo proposed a scenario to study the Schwinger effect in the context of the AdS/CFT correspondence. The production rate of quark–antiquark pairs was computed in the Coulomb phase. In particular, it provided the critical value of external electric field, above which particles are freely created and the vacuum decays catastrophically. Then the potential analysis in the holographic approach was invented and it enabled us to study the Schwinger effect in the confining phase as well. A remarkable feature of the Schwinger effect in the confining phase is to exhibit another kind of the critical value, below which the pair production cannot occur and the vacuum of the system is nonperturbatively stable. The critical value is tantamount to the confining string tension. We computed the pair production rate numerically and introduced new exponents associated with the critical electric fields.


2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zi-qiang Zhang ◽  
De-fu Hou ◽  
Yan Wu ◽  
Gang Chen

Using the AdS/CFT correspondence, we investigate the Schwinger effect in a confining D3-brane background with chemical potential. The potential between a test particle pair on the D3-brane in an external electric field is obtained. The critical fieldEcin this case is calculated. Also, we apply numerical method to evaluate the production rate for various cases. The results imply that the presence of chemical potential tends to suppress the pair production effect.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Valerie Domcke ◽  
Yohei Ema ◽  
Kyohei Mukaida

Abstract We point out an enhancement of the pair production rate of charged fermions in a strong electric field in the presence of time dependent classical axion-like background field, which we call axion assisted Schwinger effect. While the standard Schwinger production rate is proportional to $$ \exp \left(-\pi \left({m}^2+{p}_T^2\right)/E\right) $$ exp − π m 2 + p T 2 / E , with m and pT denoting the fermion mass and its momentum transverse to the electric field E, the axion assisted Schwinger effect can be enhanced at large momenta to exp(−πm2/E). The origin of this enhancement is a coupling between the fermion spin and its momentum, induced by the axion velocity. As a non-trivial validation of our result, we show its invariance under field redefinitions associated with a chiral rotation and successfully reproduce the chiral anomaly equation in the presence of helical electric and magnetic fields. We comment on implications of this result for axion cosmology, focussing on axion inflation and axion dark matter detection.


2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Wenhe Cai ◽  
Kang-le Li ◽  
Si-wen Li

Abstract Using the Witten–Sakai–Sugimoto model in the D0–D4 background, we holographically compute the vacuum decay rate of the Schwinger effect in this model. Our calculation contains the influence of the D0-brane density which could be identified as the $$\theta $$θ angle or chiral potential in QCD. Under the strong electromagnetic fields, the instability appears due to the creation of quark–antiquark pairs and the associated decay rate can be obtained by evaluating the imaginary part of the effective Euler–Heisenberg action which is identified as the action of the probe brane with a constant electromagnetic field. In the bubble D0–D4 configuration, we find the decay rate decreases when the $$\theta $$θ angle increases since the vacuum becomes heavier in the present of the glue condensate in this system. And the decay rate matches to the result in the black D0–D4 configuration at zero temperature limit according to our calculations. In this sense, the Hawking–Page transition of this model could be consistently interpreted as the confined/deconfined phase transition. Additionally there is another instability from the D0-brane itself in this system and we suggest that this instability reflects to the vacuum decay triggered by the $$\theta $$θ angle as it is known in the $$\theta $$θ-dependent QCD.


2018 ◽  
Author(s):  
Sebastian Ehrhart ◽  
Eimear M. Dunne ◽  
Hanna E. Manninen ◽  
Tuomo Nieminen ◽  
Jos Lelieveld ◽  
...  

Abstract. Two new submodels for the Modular Earth Submodel System (MESSy) were developed. The New Aerosol Nucleation submodel (NAN) includes new parameterisations of aerosol particle formation rates published in recent years. These parameterisations include ion-induced nucleation and nucleation of pure organic species. NAN calculates the rate of new particle formation based on the aforementioned parameterisations for aerosol submodels in the ECHAM/MESSy Atmospheric chemistry - Climate (EMAC) model. The Ion pair production rate, needed to calculate the ion-induced or -mediated nucleation, is described using the new submodel IONS, which provides ion pair production rates for other submodels within the MESSy framework. Both new submodels were tested in EMAC simulations. These simulations showed good agreement with ground based observations.


2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Anatoly D. Panferov ◽  
Stanislav A. Smolyansky ◽  
Andreas Otto ◽  
Burkhard Kämpfer ◽  
David B. Blaschke ◽  
...  

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