The star-delta transform (Y-Δ transform) is a mathematical technique that simplifies the analysis of an electrical circuit. It is also known by the names Y-delta, Y-Delta, Delta-Star Transformation, Star-Mesh Transformation, T-Π or T-Pi Transformation etc. It is named after the shape of the electrical circuit, which resembles the Roman letter Y and the Greek letter Δ. This circuit modification was published by Arthur Edwin Kennedy in 1899.