# Millennium Prize Problems

set of 7 mathematical problems that had not been solved by the year 2000

The Millennium Prize Problems are seven problems in mathematics that were stated by the Clay Mathematics Institute in 2000. A correct solution to any of the problems results in a US \$1,000,000 prize (sometimes called a Millennium Prize) being awarded by the institute.

## Quotes

### Solved problem

#### Poincaré conjecture

Main article: Poincaré conjecture

The official statement of the problem was given by John Milnor. A proof of this conjecture was given by Grigori Perelman in 2003.

### Unsolved problems

#### P versus NP

Main article: P versus NP problem

The official statement of the problem was given by Stephen Cook.

#### Hodge conjecture

Main article: Hodge conjecture

The official statement of the problem was given by Pierre Deligne.

#### Riemann hypothesis

Main article: Riemann hypothesis

The official statement of the problem was given by Enrico Bombieri.

#### Yang–Mills existence and mass gap

• One should mention right at the start that one still does not understand whether quantum mechanics and special relativity are compatible at a fundamental level in our Minkowski four-space world. One generally assumes that this means finding a complete Yang-Mills gauge theory or the interaction of gauge fields with fermionic matter fields, the simplest form being quantum chromodynamics (QCD). Associated with this picture is the belief that the fundamental vector meson excitations are massive (as opposed to photons, which arise in the limiting case of an abelian gauge symmetry. The proof of the existence of a “mass gap” appears a necessary integral part of solving the entire puzzle. This question remains one of the deepest open issues in theoretical physics, as well as in mathematics.

Basically the question remains: can one give a mathematical foundation to the theory of fields in four-dimensions? In other words, when do quantum mechanics and special relativity lie on the same footing as the "classical physics" of Newton, Maxwell, Einstein, or Schrödinger—all of which fits into a mathematical framework that we describe as the language of physics. This glaring gap in our fundamental knowledge even dwarfs questions of whether there are other more complicated and sophisticated approaches to physics—those that incorporate gravity, strings, or branes—for understanding their fundamental significance lies far in the future. In fact, one believes that string proposals, if they can be fully implemented, have limiting cases that appear as relativistic quantum fields, just as relativistic quantum fields describe non-relativistic quantum theory and classical physics in various limiting cases.

The official statement of the problem was given by Arthur Jaffe and Edward Witten.

#### Navier–Stokes existence and smoothness

The official statement of the problem was given by Charles Fefferman.

#### Birch and Swinnerton-Dyer conjecture

The official statement of the problem was given by Andrew Wiles.