"Acta Mathematica" by G. Mittag-Leffler is a pioneering mathematical journal that showcases groundbreaking research across various fields of pure and applied mathematics. Renowned for its rigorous standards and influential papers, the publication has played a vital role in advancing mathematical knowledge in the late 19th and early 20th centuries. It features innovative theories, proofs, and methodologies that have shaped modern mathematics, making it an essential resource for researchers and enthusiasts eager to explore the depths of mathematical discovery. Acta Mathematica is an unchanged, high-quality reprint of the original edition of 1882.