论文标题
QED阳性界限
QED positivity bounds
论文作者
论文摘要
我们将阳性边界直接应用于带有充电标量和带电的费米子（即Qed）最小耦合到重力的$ U（1）$量规理论。假设可以丢弃无质量的$ t $ channel杆，我们表明，除非在参数较低的$ cobs $λ_ {\ rm new} \ sim（e m _ {e m _ {\ rm pl}} $ coldies factor field field callies factor的范围内，否则将违反改进的阳性界限，除非在参数较低的$λ_ {\ rm new} \ sim（e m _ {e m _ {e m _ {e m _ {e m _ {e m _ {e m _ {e m _ {e m _ {e m _ {猜想。这与以前的治疗形成鲜明对比，这些治疗的重点是将阳性界限应用于低能量引力的Euler-Heisenberg有效理论。我们强调的是，在可以丢弃极点的假设下，低距离是应用阳性界限的结果。我们猜想另一种解决方案，即允许使用少量的负面力，与脱钩限制一致，并且与标准的紫外线完成（包括弱耦合）不冲突。
We apply positivity bounds directly to a $U(1)$ gauge theory with charged scalars and charged fermions, i.e. QED, minimally coupled to gravity. Assuming that the massless $t$-channel pole may be discarded, we show that the improved positivity bounds are violated unless new physics is introduced at the parametrically low scale $Λ_{\rm new} \sim (e m M_{\rm pl})^{1/2}$, consistent with similar results for scalar field theories, far lower than the scale implied by the weak gravity conjecture. This is sharply contrasted with previous treatments which focus on the application of positivity bounds to the low energy gravitational Euler-Heisenberg effective theory only. We emphasise that the low-cutoff is a consequence of applying the positivity bounds under the assumption that the pole may be discarded. We conjecture an alternative resolution that a small amount of negativity, consistent with decoupling limits, is allowed and not in conflict with standard UV completions, including weakly coupled ones.
