这一项就是我们要的Chern Simons term。得到了这个表达式之后，我们可以来解释为什么这一项具有拓扑性。举一个简单的例子，根据弯曲时空背景下的QFT，对于实标量场我们可以写出其Lagrangian满足L=−g12(gμν∂μφ∂νφ−m2φ2)，其中g=detgμνg=\mathrm{det}g_{\mu\nu}，很明显这个Lagrangian是度规...
现在我们来考虑一个4维的系统,我们设想相同的Chern-Simons term也可以在4维系统中找到,只要求其对应的运动方程,我们就得到了4维TI的拓扑响应。更多细节可以看XL Qi的综述和Bernevig的拓扑绝缘体一书的第13章。 其中,4D TI的有效作用量为 S_{\mathrm{eff}}=\frac{C_{2}}{24 \pi^{2}} \int d^{4} ...
Chern-Simons termmonopolelinear confinementelectric chargecompact (2+1)-dimensional QEDMonopoles lead to linear confinement of electric charge in compact (2 + 1)-dimensional QED. On the other hand, the addition of a Chern-Simons term renders the Coulomb interaction short-range. We consider here ...
但这样的解看起来像是一个pure gauge term,如果我们取 \lambda=-\frac{e}{2\pi\kappa}\sum_{a=1}^iarg(\bm{r}-\bm{r}_a) ,在规范变换下,gauge potential就消失了! 但不巧的是, arg(\bm{r}) 是多值的,做完规范变换,相应的描述这个系统的场 \psi(\bm{r}) 也需要相应的变为 \psi'(\bm{r...
It is shown that topological massive gravity augmented by the triadic gravitational Chern-Simons first order term is a curved a pure spin-2 action. This model contains two massive spin-2 excitations. However, since its light-front energy is not semidefinite positive, this double CS-action does ...
fermion，因为2+1D massless fermion具有parity anomaly，可以cancel bulk里面θ-term的chiral anomaly，这...
Field redefinitions in the low-energy effective action of the heterotic string are discussed. A field redefinition is constructed which generates the local counterterm that transforms the Lorentz into the gravitational form of the anomaly. We also discuss the field redefinition which torsionizes the ...
(2+1)-dimensional QED with a Chern-Simons term in the ladder approximation We study dynamical chiral symmetry breaking in (2+1)-dimensional QED with a Chern-Simons term. It is observed that the Chern-Simons term improves the infra... Kye,Kim - 《Physical Review D Particles & Fields》 被...
A gauge theory with a discrete group H in (2 + 1)-dimensional space-time is known to describe (non-abelian) anyons. We study the effect of adding a Chern-Simons term to such a theory. As in a previous paper, we emphasize the algebraic structure underlying a discrete H gauge theory, ...
Chern-Simons termWe perform the complete bosonization of 2+1 dimensional QED with one fermionic flavor in the Hamiltonian formalism. The fermion operators are explicitly constructed in terms of the vector potential and the electric field. We carefully specify the regularization procedure involved in ...