论文标题
磁场中的QGP通用性？
QGP universality in a magnetic field?
论文作者
论文摘要
我们使用自上而下的全息模型来研究外部磁场中强耦合夸克 - 杜伦等离子体的热量。我们在$ {\ cal n} = 8 $中的一致截断范围内确定不同的保险和非统一理论，在五个维度（包括stu型号，测量$ {\ cal n} = 2^*$理论）中，并显示横向与长度压力$ p_t/p $ p_l $ s a n af/p $ t $ t.折叠成一个“通用”曲线，以广泛的伴随超人质量$ m $ $。我们强调的是，这并不意味着磁响应中任何隐藏的普遍性，因为其他可观察到的东西没有表现出任何普遍性。取而代之的是，观察到的$ p_t/p_l $中观察到的崩溃仅仅是由于状态方程在（可自由调节的）重新归一化量表上的强烈依赖性：换句话说，这只是一个合适的伪像。值得注意的是，我们确实发现了$ {\ cal n} = 2^*$量学理论中的不同普遍性：我们证明磁化化的$ {\ cal n} = 2^*$ plasma在$ t_ {crit}/\ sqrt {b} $ by where varies $ 2 $ 2 \％$ $（或$ 2 \％$ s）上具有关键点的关键点[0，\ infty）$。在关键时期，对于$ m/\ sqrt {b} $的巨大值，该理论的有效中心收费为$ \ propto \ sqrt {b}/m $。
We use top-down holographic models to study the thermal equation of state of strongly coupled quark-gluon plasma in external magnetic field. We identify different conformal and non-conformal theories within consistent truncations of ${\cal N}=8$ gauged supergravity in five dimensions (including STU models, gauged ${\cal N}=2^*$ theory) and show that the ratio of the transverse to the longitudinal pressure $P_T/P_L$ as a function of $T/\sqrt{B}$ can be collapsed to a 'universal' curve for a wide range of the adjoint hypermultiplet masses $m$. We stress that this does not imply any hidden universality in magnetoresponse, as other observables do not exhibit any universality. Instead, the observed collapse in $P_T/P_L$ is simply due to a strong dependence of the equation of state on the (freely adjustable) renormalization scale: in other words, it is simply a fitting artifact. Remarkably, we do uncover a different universality in ${\cal N}=2^*$ gauge theory in the external magnetic field: we show that magnetized ${\cal N}=2^*$ plasma has a critical point at $T_{crit}/\sqrt{B}$ which value varies by $2\%$ (or less) as $m/\sqrt{B}\in [0,\infty)$. At criticality, and for large values of $m/\sqrt{B}$, the effective central charge of the theory scales as $\propto \sqrt{B}/m$.
