Ivar Fredholm was a Swedish mathematician known for his significant contributions to functional analysis and operator theory. He is best recognized for the development of the Fredholm theory, which deals with integral equations and linear operators. His work laid the foundation for understanding the properties of Fredholm operators, which are crucial in various areas of mathematics and applied sciences. Born in 1866, Fredholm's research has had a lasting impact on mathematics, influencing fields such as quantum mechanics and signal processing. He passed away in 1927, but his legacy continues through the ongoing study of his theories and their applications in modern mathematics.