9,231 research outputs found
The Elementary Particles as Quantum Knots in Electroweak Theory
We explore a knot model of the elementary particles that is compatible with
electroweak physics. The knots are quantized and their kinematic states are
labelled by , irreducible representations of , where j =
N/2, m = w/2, m' = (r+1)/2 and (N,w,r) designate respectively the number of
crossings, the writhe, and the rotation of the knot. The knot quantum numbers
(N,w,r) are related to the standard isotopic spin quantum numbers
by , where is the hypercharge. In this
model the elementary fermions are low lying states of the quantum trefoil (N=3)
and the gauge bosons are ditrefoils (N=6). The fermionic knots interact by the
emission and absorption of bosonic knots. In this framework we have explored a
slightly modified standard electroweak Lagrangian with a slightly modified
gauge group which agrees closely but not entirely with standard electroweak
theory.Comment: 29 pages; LaTex fil
Masses and Interactions of q-Fermionic Knots
The q-electroweak theory suggests a description of elementary particles as
solitons labelled by the irreducible representations of SU_q(2). Since knots
may also be labelled by the irreducible representations of SU_q(2), we study a
model of elementary particles based on a one-to-one correspondence between the
four families of Fermions (leptons, neutrinos, (-1/3) quarks, (2/3) quarks) and
the four simplest knots (trefoils). In this model the three particles of each
family are identified with the ground and first two excited states of their
common trefoil. Guided by the standard electroweak theory we calculate
conditions restricting the masses of the fermions and the interactions between
them.
In its present form the model predicts a fourth generation of fermions as
well as a neutrino spectrum. The same model with q almost equal to 1 is
compatible with the Kobayashi-Maskawa matrix. Depending on the test of these
predictions, the model may be refined.Comment: 40 pages, 2 figures, latex forma
Supply or Demand: Why is the Market for Long-Term Care Insurance So Small?
Long-term care represents one of the largest uninsured financial risks facing the elderly in the United States. Whether the small size of this market is driven primarily by supply side market imperfections or by limitations to demand, however, is unresolved, largely due to the paucity of data about the structure of the private market. We provide what is to our knowledge the first empirical evidence on the pricing and benefit structure of long-term care insurance policies. We estimate that the typical policy purchased by a 65-year old has an average pricing load of about 18 percent and has a very limited benefit structure, covering only one-third of the expected present discounted value of long-term care expenditures. These findings are consistent with the presence of supply side market imperfections. However, we also find enormous gender differences in pricing -- typical loads are 44 cents on the dollar for men but better than actuarially fair for women -- that do not translate into differences in coverage. And, although purchased policies provide limited benefits, we demonstrate that more comprehensive policies are widely-available at similar loads, but are rarely purchased. These findings suggest that while supply-side market imperfections exist, they are not the primary cause of the small size of the private long-term care insurance market.
- …