9,231 research outputs found

    The Elementary Particles as Quantum Knots in Electroweak Theory

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    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 DmmjD^j_{mm'}, irreducible representations of SUq(2)SU_q(2), 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 (t,t3,t0)(t,t_3,t_0) by (t=N/6,t3=w/6,t0=(r+1)/6)(t=N/6,t_3=-w/6,t_0=-(r+1)/6), where t0t_0 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

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    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?

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    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.
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