标题： 光锥哈密顿量用于伊辛场理论 I：T < T_c 显示英文标题

标题： Lightcone Hamiltonian for Ising Field Theory I: T < T_c

摘要： 我们研究在光锥量子化下的低温相二维伊辛场理论（IFT），并表明积分掉零模会产生一个非常紧凑的有效光锥相互作用形式，该形式依赖于有限体积真空期望值的$\sigma$算符。 这种形式在光锥希尔伯特空间的共形基下最自然地被理解。 我们进一步验证了这种简单形式能够以高精度重现从可积性方法得到的磁扰动 IFT 的谱、$c$函数和形式因子的结果。 对于参数的非可积一般值，我们也计算了上述可观测量，并将我们的数值结果与等时截断的结果进行比较。 特别是，我们报告了各种束缚态形式因子以及应力张量谱密度的新测量结果。 我们发现，应力张量谱密度提供了额外的证据，表明 IFT 的某些共振即使在一般的强耦合下也非常窄。 附录中包含了构建有效哈密顿量的显式示例代码。 显示英文摘要

摘要： We study 2d Ising Field Theory (IFT) in the low-temperature phase in lightcone quantization, and show that integrating out zero modes generates a very compact form for the effective lightcone interaction that depends on the finite volume vacuum expectation value of the $\sigma$ operator. This form is most naturally understood in a conformal basis for the lightcone Hilbert space. We further verify that this simple form reproduces to high accuracy results for the spectra, the $c$-function, and the form-factors from integrability methods for the magnetic deformation of IFT. For generic non-integrable values of parameters we also compute the above observables and compare our numeric results to those of equal-time truncation. In particular, we report on new measurements of various bound-state form-factors as well as the stress-tensor spectral density. We find that the stress tensor spectral density provides additional evidence that certain resonances of IFT are surprisingly narrow, even at generic strong coupling. Explicit example code for constructing the effective Hamiltonian is included in an appendix.