Group actions on dendrites and curves

نویسندگان
چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Minimal Group Actions on Dendrites

Minimal group actions on dendrites appear naturally in the study of 3-dimensional hyperbolic geometry. In this paper, it is shown that if a group G acts on a nondegenerate dendrite X minimally, then X admits no G-invariant measure. In particular, G cannot be amenable.

متن کامل

Group actions on curves and the lifting problem

1.1 The lifting problem The problem we are concerned with in our lectures and which we shall refer to as the lifting problem was originally formulated by Frans Oort in [17]. To state it, we fix an algebraically closed field κ of positive characteristic p. Let W (κ) be the ring of Witt vectors over κ. Throughout our notes, o will denote a finite local ring extension of W (κ) and k = Frac(o) the ...

متن کامل

Acyclic curves and group actions on affine toric surfaces

We show that every irreducible, simply connected curve on a toric affine surface X over C is an orbit closure of a Gm-action on X . It follows that up to the action of the automorphism group Aut(X) there are only finitely many non-equivalent embeddings of the affine line A in X . A similar description is given for simply connected curves in the quotients of the affine plane by small finite line...

متن کامل

Effective Curves on M 0,n from Group Actions

We study new effective curve classes on the moduli space of stable pointed rational curves given by the fixed loci of subgroups of the permutation group action. We compute their numerical classes and provide a strategy for writing them as effective linear combinations of F-curves, using Losev-Manin spaces and toric degeneration of curve classes.

متن کامل

Galois actions on Q - curves and

We prove two “large images” results for the Galois representations attached to a degree d Q-curve E over a quadratic field K: if K is arbitrary, we prove maximality of the image for every prime p > 13 not dividing d, provided that d is divisible by q (but d 6= q) with q = 2 or 3 or 5 or 7 or 13. If K is real we prove maximality of the image for every odd prime p not dividing dD, where D = disc(...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Annales de l’institut Fourier

سال: 2018

ISSN: 0373-0956,1777-5310

DOI: 10.5802/aif.3209