905 research outputs found
Canonically Relativistic Quantum Mechanics: Representations of the Unitary Semidirect Heisenberg Group, U(1,3) *s H(1,3)
Born proposed a unification of special relativity and quantum mechanics that
placed position, time, energy and momentum on equal footing through a
reciprocity principle and extended the usual position-time and energy-momentum
line elements to this space by combining them through a new fundamental
constant. Requiring also invariance of the symplectic metric yields U(1,3) as
the invariance group, the inhomogeneous counterpart of which is the canonically
relativistic group CR(1,3) = U(1,3) *s H(1,3) where H(1,3) is the Heisenberg
Group in 4 dimensions and "*s" is the semidirect product. This is the
counterpart in this theory of the Poincare group and reduces in the appropriate
limit to the expected special relativity and classical Hamiltonian mechanics
transformation equations. This group has the Poincare group as a subgroup and
is intrinsically quantum with the Position, Time, Energy and Momentum operators
satisfying the Heisenberg algebra. The representations of the algebra are
studied and Casimir invariants are computed. Like the Poincare group, it has a
little group for a ("massive") rest frame and a null frame. The former is U(3)
which clearly contains SU(3) and the latter is Os(2) which contains SU(2)*U(1).Comment: 18 pages, PDF, to be published in J. Math. Phys., Mathematica 3.0
computation files available from author at [email protected]
Relativity group for noninertial frames in Hamilton's mechanics
The group E(3)=SO(3) *s T(3), that is the homogeneous subgroup of the Galilei
group parameterized by rotation angles and velocities, defines the continuous
group of transformations between the frames of inertial particles in Newtonian
mechanics. We show in this paper that the continuous group of transformations
between the frames of noninertial particles following trajectories that satisfy
Hamilton's equations is given by the Hamilton group Ha(3)=SO(3) *s H(3) where
H(3) is the Weyl-Heisenberg group that is parameterized by rates of change of
position, momentum and energy, i.e. velocity, force and power. The group E(3)
is the inertial special case of the Hamilton group.Comment: Final versio
Jacobi Group Symmetry of Hamilton's Mechanics
We show that the diffeomorphisms of an extended phase space with time,
energy, momentum and position degrees of freedom that leave invariant the
symplectic 2-form and and a degenerate orthogonal metric dt^2 locally satisfy
Hamilton's equations up to the usual canonical transformations on the
position-momentum subspace
Reciprocal relativity of noninertial frames: quantum mechanics
Noninertial transformations on time-position-momentum-energy space {t,q,p,e}
with invariant Born-Green metric ds^2=-dt^2+dq^2/c^2+(1/b^2)(dp^2-de^2/c^2) and
the symplectic metric -de/\dt+dp/\dq are studied. This U(1,3) group of
transformations contains the Lorentz group as the inertial special case. In the
limit of small forces and velocities, it reduces to the expected Hamilton
transformations leaving invariant the symplectic metric and the nonrelativistic
line element ds^2=dt^2. The U(1,3) transformations bound relative velocities by
c and relative forces by b. Spacetime is no longer an invariant subspace but is
relative to noninertial observer frames. Born was lead to the metric by a
concept of reciprocity between position and momentum degrees of freedom and for
this reason we call this reciprocal relativity.
For large b, such effects will almost certainly only manifest in a quantum
regime. Wigner showed that special relativistic quantum mechanics follows from
the projective representations of the inhomogeneous Lorentz group. Projective
representations of a Lie group are equivalent to the unitary reprentations of
its central extension. The same method of projective representations of the
inhomogeneous U(1,3) group is used to define the quantum theory in the
noninertial case. The central extension of the inhomogeneous U(1,3) group is
the cover of the quaplectic group Q(1,3)=U(1,3)*s H(4). H(4) is the
Weyl-Heisenberg group. A set of second order wave equations results from the
representations of the Casimir operators
Reciprocal relativity of noninertial frames and the quaplectic group
Newtonian mechanics has the concept of an absolute inertial rest frame.
Special relativity eliminates the absolute rest frame but continues to require
the absolute inertial frame. General relativity solves this for gravity by
requiring particles to have locally inertial frames on a curved position-time
manifold. The problem of the absolute inertial frame for other forces remains.
We look again at the transformations of frames on an extended phase space with
position, time, energy and momentum degrees of freedom. Under nonrelativistic
assumptions, there is an invariant symplectic metric and a line element dt^2.
Under special relativistic assumptions the symplectic metric continues to be
invariant but the line elements are now -dt^2+dq^2/c^2 and dp^2-de^2/c^2. Max
Born conjectured that the line element should be generalized to the pseudo-
orthogonal metric -dt^2+dq^2/c^2+ (1/b^2)(dp^2-de^2/c^2). The group leaving
these two metrics invariant is the pseudo-unitary group of transformations
between noninertial frames. We show that these transformations eliminate the
need for an absolute inertial frame by making forces relative and bounded by b
and so embodies a relativity that is 'reciprocal' in the sense of Born. The
inhomogeneous version of this group is naturally the semidirect product of the
pseudo-unitary group with the nonabelian Heisenberg group. This is the
quaplectic group. The Heisenberg group itself is the semidirect product of two
translation groups. This provides the noncommutative properties of position and
momentum and also time and energy that are required for the quantum mechanics
that results from considering the unitary representations of the quaplectic
group.Comment: Substantial revision, Publicon LaTe
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