标题： RNA冻结相变的场论 显示英文标题

标题： Field Theory of the RNA Freezing Transition

摘要： RNA的折叠受到熵与随机或看似随机的序列之间的竞争影响，其中熵在高温下起主导作用，而序列则决定了低温相。已知从数值模拟中得知，对于随机序列和生物序列，高温相和低温相是不同的，例如描述两个碱基配对概率的指数rho在高温相中为3/2，在低温（玻璃）相中约为4/3。在这里，我们为随机序列提出了一个场论，用于描述区分高温相和低温相的相变。我们通过证明其基础理论在微扰理论的所有阶次上都是可重整化的，从而确立了后者的存在。我们通过一个显式的二环计算验证了这一结果，该计算在相变点得到rho约为1.36，以及包括对外加外力（变性相变）的响应在内的多种其他临界指数。 显示英文摘要

摘要： Folding of RNA is subject to a competition between entropy, relevant at high temperatures, and the random, or random looking, sequence, determining the low- temperature phase. It is known from numerical simulations that for random as well as biological sequences, high- and low-temperature phases are different, e.g. the exponent rho describing the pairing probability between two bases is rho = 3/2 in the high-temperature phase, and approximatively 4/3 in the low-temperature (glass) phase. Here, we present, for random sequences, a field theory of the phase transition separating high- and low-temperature phases. We establish the existence of the latter by showing that the underlying theory is renormalizable to all orders in perturbation theory. We test this result via an explicit 2-loop calculation, which yields rho approximatively 1.36 at the transition, as well as diverse other critical exponents, including the response to an applied external force (denaturation transition).