149,849 research outputs found

    A study of the research done on the gifted child from 1952 to the present day.

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    Thesis (Ed.M.)--Boston Universit

    The origin of order in random matrices with symmetries

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    From Noether's theorem we know symmetries lead to conservation laws. What is left to nature is the ordering of conserved quantities; for example, the quantum numbers of the ground state. In physical systems the ground state is generally associated with `low' quantum numbers and symmetric, low-dimensional irreps, but there is no \textit{a priori} reason to expect this. By constructing random matrices with nontrivial point-group symmetries, I find the ground state is always dominated by extremal low-dimensional irreps. Going further, I suggest this explains the dominance of J=0 g.s. even for random two-body interactions.Comment: 5 figures; contribution to "Beauty in Physics" conference in honor of Francesco Iachello, May 2012, Cocoyoc, Mexic

    Tracing the evolution of nuclear forces under the similarity renormalization group

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    I examine the evolution of nuclear forces under the similarity renormalization group (SRG) using traces of the many-body configuration-space Hamiltonian. While SRG is often said to "soften" the nuclear interaction, I provide numerical examples which paint a complementary point of view: the primary effect of SRG, using the kinetic energy as the generator of the evolution, is to shift downward the diagonal matrix elements in the model space, while the off-diagonal elements undergo significantly smaller changes. By employing traces, I argue that this is a very natural outcome as one diagonalizes a matrix, and helps one to understand the success of SRG.Comment: 6 pages, 3 figures, 1 tabl
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