Computational Number Theory Pdf

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Blossom Stemmer

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Aug 5, 2024, 2:27:51 AM8/5/24
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Inmathematics and computer science, computational number theory, also known as algorithmic number theory, is the study of computational methods for investigating and solving problems in number theory and arithmetic geometry, including algorithms for primality testing and integer factorization, finding solutions to diophantine equations, and explicit methods in arithmetic geometry.[1]Computational number theory has applications to cryptography, including RSA, elliptic curve cryptography and post-quantum cryptography, and is used to investigate conjectures and open problems in number theory, including the Riemann hypothesis, the Birch and Swinnerton-Dyer conjecture, the ABC conjecture, the modularity conjecture, the Sato-Tate conjecture, and explicit aspects of the Langlands program.[1][2][3]

Which sort of number theory problems can be solved by using computers? For example, is it possible to determine the ring of integers in number field extensions or find the discriminant of the extensions?


In this book the author explains, among others, how to solve the basic tasks of Comptuational Algebraic Number Theory. So how to calculate with algebraic numbers, calculating rings of integers, discriminant, Galois group and so on. Also, certain methods of factorisation are discussed as well as question on arithemtic of polynomials.


Roughly, the functionality of Matlab is not geared towards number theory. Mathematica and Maple offer more here, certainly useful for some things and for some even very good as far as I know, but not specialized for number theory. An important (non-free) other program is Magma, which is I think considered as leading for certain number theory (related) tasks.


And, last but certainly not least, there is a large free open-source project Sage that has a certain focus on number theory (the founder William Stein is a number theorist). It inculdes (more or less) Pari and much other free open-source math software; some directly or indirectly relevant for number theory.


If you search for a possibility to do computational number theory and to potentially do something of lasting value, I would recommend that you look into Sage. Its web page offers a lot of documentation but also (number theory) papers written with the help of Sage. Yet also (number theory) lecture notes and text books with a computational slant. The developpment process seems very open and there are plenty of tasks to be done (from small to large, from beginner friendly to research level).[Note: I did not contribute anything to Sage, I only followed its developpment from a distance but somewhat in detail.]


You might be interested in Project Euler ( ), which guides you through solving progressively more difficult math problems using computer programming. This is not exactly what you asked about, but is rather a complement to quid's excellent answer.


There's a different sort of number theory, combinatorial, that benefits tremendously from computation and experimentation. An excellent website to get you started is Borwein and Bailey (responsible for that website) are two of the champions of using computers to find new results, and Zeilberger is the godfather of using computers to prove combinatorial results.


It is true that Mathematica and other commercial/proprietary mathematics packages have widespread commercial use, but the non-public-ness of their actual algorithms, etc., is rather disappointing if one cares about what is actually happening. Bad enough that we are not able to personally witness the correctness of a large-integer computation, but even worse if we cannot even view the algorithms involved. Also, as computer languages, they have considerable failings, I think.


My favorite book on computational number theory is A Course in Computational Number Theory by David Bressoud and Stan Wagon, which is based on Mathematica. It contains lots of Mathematica code, printed right in the body of the text, and you can easily implement this code to both duplicate the results in the text and explore with your own problems. Several of the homework problems are of the form "Modify the code of Algorithm 1 so that it performs...," thereby saving you lots of programming time. It comes with an Appendix on basic Mathematica coding, and although I'm an expert Mathematica programmer and do not need that background, I have the sense that anyone computer-literate can implement the code in the text and understand the language. You also get to exploit numerous number-theoretic functions built into the language, on prime factorization, totients, and so on.


I would say my favorite book on number theory is An Illustrated Theory of Numbers by Martin H. Weissman, whose graphical presentations really make the discipline memorable and help develop intuition and insight. This book does not treat the computational aspects of number theory, however, and hence is not quite right for the question as asked.


Computational number theory, also known as algorithmic number theory is a branch of number theory. It focuses on identifying and using efficient computational methods and algorithms to solve multiple problems in number theory as well as arithmetic geometry.




Computational number theory studies whole numbers and, to some extent, even rational and algebraic numbers. It is the study of computations with these types of numbers. Some of the tasks carried out by computational number theorists include:


Computational number theory is used widely in cryptography. It is used in elliptic curve cryptography, RSA, and post-quantum cryptography. The theory is even used to investigate speculations, notions, and open problems in number theory. It is because of its connections with cryptography that number theory has applications in computer science.




Programs that are used to test a conjecture might either look for a counterexample to disprove the conjecture or verify the conjecture for several cases, thus supporting it. Computer algebra systems employed by scientists and engineers make use of algorithms of number theory to carry out their basic steps.




Quite often, the algorithms used in computational number theory will work exclusively with integers, but this is not always the case. The analysis of such algorithms frequently draws from other areas of mathematics.


Number theory is unique among modern mathematical disciplines because it has whole lot of problems, some of which are extremely hard, that can be stated in terms that are comprehensible to someone who is not a specialist.




Speeding up primality testing is a research topic currently. The majority of fast cryptographic algorithms that need primes tend to pick probable primes due to the fact that probable prime tests are much faster than true prime tests. But real primality tests are speeding up and could soon be fast enough for them to be used in programs like the Secure Sockets Layer.




Prime factorization is the process of determining the prime factors of a number. This is considered to be a computationally hard problem and there are multiple algorithms with varying levels of sophistication that are used to solve this problem.




Direct search factorization is the simplest way to find the factors. It uses trial division of all possible factors. However, it is only practical for small numbers. Computational number theory is useful for the prime factorization of larger numbers.


As we mentioned earlier, faster primality testing is one of the important research topics right now. In addition to this, algorithms for factoring large integers are another major hot topic in computational number theory. The Cunningham Project is one of the benchmarks for the current ability to factor integers. The fastest general factoring algorithm right now is the General Number Field Sieve. It starts by choosing a suitable polynomial that determines how long


There still is research going on in Diophantine equations (equations with integer coefficients to be solved with integer values for the variables). Many more equations are yet to be solved in whole numbers.


number theory, especially on the use of random matrix theory (from physics) to attack the Riemann Hypothesis (a Clay Millennium Problem, is a part of analytic number theory, which employs the analytic methods of calculus and complex analysis to understand the integers.


More than other fields in mathematics, combinatorial number theory is considered to be a recreational field. It is studied lightly, without any real concern for applications. It is encountered quite a lot in the form of problems as well as in classical results.




This subject is interdisciplinary in nature and incorporates ideas from a wide range of different fields including harmonic analysis, graph theory, number theory, ergodic theory, discrete geometry, probability theory, as well as theoretical computer science.




This conference provided an opportunity for researchers, scholars, and practitioners to exchange ideas, share advances, and collaborate in the fields of computation, mathematical databases, number theory, and arithmetic geometry. The papers that appear in this volume record recent advances in these areas, with special focus on the LMFDB (the L-Functions and Modular Forms Database), an online resource for mathematical objects arising in the Langlands program and the connections between them.


Our common perspective is that advances in computational techniques accelerate research in arithmetic geometry and number theory, both as a source of data and examples, and as an impetus for effective results. The dynamic interplay between experiment, theory, and computation has historically played a pivotal role in the development of number theory. In the 18th and 19th centuries Euler and Gauss undertook extensive calculations by hand in the pursuit of data to help formulate and refine conjectures, and as a source of counter examples. In the 20th century systematic computations of elliptic curves and their L-functions led to the formulation of the Sato-Tate and modularity conjectures, both of which have now been proved, and the conjecture of Birch and Swinnerton-Dyer, which remains open but has been proved in some special cases.

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