TY - JOUR ID - Cho2017 LB - Cho2017 AU - Cho, Ilwoo TI - Non-factorizable C-valued functions induced by finite connected graphs ST - Non-factorizable C-valued functions induced by finite connected graphs JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2017 VL - 37 IS - 2 SP - 225 EP - 263 DO - http://dx.doi.org/10.7494/OpMath.2017.37.2.225 UR - http://dx.doi.org/10.7494/OpMath.2017.37.2.225 AB - In this paper, we study factorizability of \(\mathbb{C}\)-valued formal series at fixed vertices, called the graph zeta functions, induced by the reduced length on the graph groupoids of given finite connected directed graphs. The construction of such functions is motivated by that of Redei zeta functions. In particular, we are interested in (i) "non-factorizability" of such functions, and (ii) certain factorizable functions induced by non-factorizable functions. By constructing factorizable functions from our non-factorizable functions, we study relations between graph zeta functions and well-known number-theoretic objects, the Riemann zeta function and the Euler totient function. KW - directed graphs KW - graph groupoids KW - Redei zeta functions KW - graph zeta functions KW - non-factorizable graphs KW - gluing on graphs SN - 1232-9274 ER -