@article {655,
	title = {Critical points of coupled vector-Ising systems. Exact results},
	journal = {J. Phys. A. Math. Theor.},
	volume = {52},
	year = {2019},
	pages = {35LT02},
	abstract = {We show that scale-invariant scattering theory allows to exactly determine the critical points of two-dimensional systems with coupled <em>O</em>(<em>N</em>) and Ising order parameters. The results are obtained for <em>N</em> continuous and include criticality of the loop gas type. In particular, for <em>N</em> = 1 we exhibit three critical lines intersecting at the Berezinskii-Kosterlitz-Thouless transition point of the Gaussian model and related to the Z$_{4}$ symmetry of the isotropic Ashkin-Teller model. For <em>N</em> = 2 we classify the critical points that can arise in the XY-Ising model and provide exact answers about the critical exponents of the fully frustrated XY model.},
	doi = {10.1088/1751-8121/ab3055},
	url = {https://iopscience.iop.org/article/10.1088/1751-8121/ab3055},
	author = {Gesualdo Delfino and Noel M. Lamsen}
}