Kν⁡(z)={12⁢π⁢ⅈ⁢ⅇν⁢π⁢ⅈ/2⁢Hν(1)⁡(z⁢ⅇπ⁢ⅈ/2),-π≤ph⁡z≤12⁢π,-12⁢π⁢ⅈ⁢ⅇ-ν⁢π⁢ⅈ/2⁢Hν(2)⁡(z⁢ⅇ-π⁢ⅈ/2),-12⁢π≤ph⁡z≤π.