A probability measure is a mathematical function that assigns a non-negative real number to subsets of a given sample space, representing the likelihood of events within a probability space. It satisfies the axioms of probability, ensuring that the measure of the entire sample space is one and that the measure of the union of mutually exclusive events is the sum of their measures.
A prime ideal in a ring is an ideal whose complement is multiplicatively closed, meaning if a product of two elements is in the ideal, then at least one of the elements is in the ideal. Prime ideals are fundamental in algebraic geometry and commutative algebra as they generalize the notion of prime numbers to more abstract algebraic structures, serving as building blocks for the structure of rings.
A Dedekind domain is an integral domain in which every nonzero proper ideal factors uniquely into a product of prime ideals, making it a generalization of the ring of integers. It plays a critical role in algebraic number theory and algebraic geometry due to its ideal-theoretic properties and connections to Noetherian rings and divisors.
Valuation theory is a branch of mathematics that deals with the assessment of the size or 'value' of elements within a field, which helps in understanding the structure of the field itself. It provides a framework for analyzing algebraic, number-theoretic, and topological properties by using valuations to measure the 'distance' between elements.
The splitting of primes refers to the behavior of prime numbers in ring extensions, particularly in the context of algebraic number theory, where a prime ideal in a base ring may decompose into a product of prime ideals in an extension ring. This phenomenon is crucial for understanding the arithmetic properties of number fields and has applications in areas such as class field theory and the study of Galois groups.
The Hilbert class field of a number field is the maximal unramified abelian extension of that field, where every ideal becomes principal. It plays a crucial role in algebraic number theory as it connects the arithmetic of the number field with its ideal class group, providing insights into the structure of the field's extensions.