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Hodge-Tate Weight


A Hodge-Tate weight of a p-adic representation V of the absolute Galois group of a finite extension K/Q_p is an integer appearing in its Hodge-Tate decomposition after extension to the completed algebraic closure C_p. For a finite-dimensional Q_p representation, the convention here writes that decomposition as

 C_p tensor _(Q_p)V= direct sum _iC_p(-i)^(m_i).

The weights are the integers i with multiplicities m_i. The representation is Hodge-Tate when such a finite decomposition exists, and C_p(-i) has cyclotomic action of exponent -i. Thus the cyclotomic representation Q_p(1) has weight -1 in this convention. Some authors use the opposite sign.

The regularity condition in the two-dimensional Fontaine-Mazur modularity assertion requires distinct Hodge-Tate weights.


See also

Absolute Galois Group, de Rham Representation, Fontaine-Mazur Conjecture, Galois Representation, Tate Twist

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References

Brinon, O. and Conrad, B. CMI Summer School Notes on p-adic Hodge Theory (Preliminary Version). June 24, 2009. https://math.stanford.edu/~conrad/papers/notes.pdf.Emerton, M. "Local-Global Compatibility in the p-adic Langlands Programme for GL_2/Q." Draft, Mar. 23, 2011. https://math.uchicago.edu/~emerton/pdffiles/lg.pdf.

Cite this as:

Weisstein, Eric W. "Hodge-Tate Weight." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Hodge-TateWeight.html

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