In geometry, the Petr–Douglas–Neumann theorem (or the PDN-theorem) is a result concerning arbitrary planar polygons.
 The theorem asserts that a certain procedure when applied to an arbitrary polygon always yields a regular polygon having the same number of sides as the initial polygon.
 The theorem was first published by Karel Petr (1868–1950) of Prague in 1908.
 The theorem was independently rediscovered by Jesse Douglas (1897–1965) in 1940 and also by B H Neumann (1909–2002) in 1941.
 The naming of the theorem as "Petr–Douglas–Neumann theorem", or as the "PDN-theorem" for short, is due to Stephen B Gray.
 This theorem has also been called Douglas’s theorem, the Douglas–Neumann theorem, the Napoleon–Douglas–Neumann theorem and Petr’s theorem.
In the mathematical subject of group theory, the Grushko theorem or the Grushko-Neumann theorem is a theorem stating that the rank (that is, the smallest cardinality of a generating set) of a free product of two groups is equal to the sum of the ranks of the two free factors.
 The theorem was first obtained in a 1940 article of Grushko and then, independently, in a 1943 article of Neumann.
In physics, the no-communication theorem is a no-go theorem from quantum information theory which states that, during measurement of an entangled quantum state, it is not possible for one observer, by making a measurement of a subsystem of the total state, to communicate information to another observer.
 The theorem is important because, in quantum mechanics, quantum entanglement is an effect by which certain widely separated events can be correlated in ways that suggest the possibility of instantaneous communication.
 The no-communication theorem gives conditions under which such transfer of information between two observers is impossible.
 These results can be applied to understand the so-called paradoxes in quantum mechanics, such as the EPR paradox, or violations of local realism obtained in tests of Bell's theorem.
 In these experiments, the no-communication theorem shows that failure of local realism does not lead to what could be referred to as "spooky communication at a distance" (in analogy with Einstein's labeling of quantum entanglement as "spooky action at a distance").
Grete (Henry-)Hermann (March 2, 1901 – April 15, 1984) was a German mathematician and philosopher noted for her work in mathematics, physics, philosophy and education.
 She is noted for her early philosophical work on the foundations of quantum mechanics, and is now known most of all for an early, but long-ignored refutation of a "no-hidden-variable theorem" by John von Neumann.
 The disputed theorem and the fact that Hermann's critique of this theorem remained nearly unknown for decades are considered to have had a strong influence on the development of quantum mechanics.
In physics, the no-deleting theorem of quantum information theory is a no-go theorem which states that, in general, given two copies of some arbitrary quantum state, it is impossible to delete one of the copies.
 It is a time-reversed dual to the no-cloning theorem, which states that arbitrary states cannot be copied.
 This theorem seems remarkable, because, in many senses, quantum states are fragile; the theorem asserts that, in a particular case, they are also robust.
 Physicist Arun K. Pati along with Samuel L. Braunstein proved this theorem.
The free will theorem of John H. Conway and Simon B. Kochen states that if we have a free will in the sense that our choices are not a function of the past, then, subject to certain assumptions, so must some elementary particles.
 Conway and Kochen's paper was published in "Foundations of Physics" in 2006.
 They published a stronger version of the theorem in 2009.
Stephen Cole Kleene (January 5, 1909 – January 25, 1994) was an American mathematician.
 One of the students of Alonzo Church, Kleene, along with Rózsa Péter, Alan Turing, Emil Post, and others, is best known as a founder of the branch of mathematical logic known as recursion theory, which subsequently helped to provide the foundations of theoretical computer science.
 Kleene's work grounds the study of which functions are computable.
 A number of mathematical concepts are named after him: Kleene hierarchy, Kleene algebra, the Kleene star (Kleene closure), Kleene's recursion theorem and the Kleene fixpoint theorem.
 He also invented regular expressions, and made significant contributions to the foundations of mathematical intuitionism.
Foundations of Physics is a monthly journal "devoted to the conceptual bases and fundamental theories of modern physics and cosmology, emphasizing the logical, methodological, and philosophical premises of modern physical theories and procedures".
 The journal publishes results and observations based on fundamental questions from all fields of physics, including: quantum mechanics, quantum field theory, special relativity, general relativity, string theory, M-theory, cosmology, thermodynamics, statistical physics, and quantum gravity
In the mathematical field of group theory, the Kurosh subgroup theorem describes the algebraic structure of subgroups of free products of groups.
 The theorem was obtained by Alexander Kurosh, a Russian mathematician, in 1934.
 Informally, the theorem says that every subgroup of a free product is itself a free product of a free group and of its intersections with the conjugates of the factors of the original free product.
The Nielsen–Ninomiya theorem is a no-go theorem in physics, in particular in lattice gauge theory, concerning the possibility of defining a theory of chiral fermions on a lattice in even dimensions.
 The theorem can be stated as follows: let formula_1 be the (Euclidean) action describing fermions formula_2 on a regular lattice of even dimensions with periodic boundary conditions, and suppose that "S" is local, hermitian and translation invariant; then the theory describes as many left-handed as right-handed states.
 Equivalently, the theorem implies that there are as many states of chirality +1 as of chirality -1.
 The proof of the theorem relies on the Poincaré-Hopf theorem or on similar results in algebraic topology.

Question: When was the Free will theorem published in the Foundations of Physics/
Answer: 2006