Let r > 0 be an integer. We present a sufficient condition for an abelian variety A over a number field k to have infinitely many quadratic twists of rank at least r, in terms of the density properties of rational points on the Kummer variety Km(Ar) of the r-fold product of A with itself. One consequence of our results is the following. Fix an abelian variety A over k, and suppose that for so…

Let G be a connected reductive group with connected center defined over Fq, with Frobenius morphism F. We parameterize all of the real-valued irreducible complex characters of GF using the Jordan decomposition of characters.

How effectively communities of scientists come together and cooperate is crucial both to the quality of research outputs and to the extent to which such outputs integrate insights, data, and methods from a variety of fields, laboratories, and locations around the globe. This essay is focused on the ensemble of material and social conditions that makes it possible for a short-term collaboration,…

Cells are the smallest known pieces of biology that are capable of independent reproduction and are therefore the simplest units that can evolve by conventional natural selection. This is problematic because even the simplest self-replicating cell-like entities seem to be too complicated to arise without the guiding hand of selection. To solve this conundrum, I argue that selection began before…

Tahun Terbit

2010

Tahun Terbit

2010

Grandmothers� availability for childcare has been shown to increase the labor force participation (LFP) and fertility of daughters. However, grandmothers� childcare availability depends highly on their LFP. When grandmothers work, intergenerational income transfers to their daughters may increase at the expense of time transfers (through childcare). Using a Two-stage Two-steps Least S…

Tahun Terbit

2010

Tahun Terbit

2010

Tahun Terbit

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