Results 1  10
of
44
Infinite Grassmannians and moduli spaces of Gbundles
 Math. Annalen
, 1994
"... These are notes for my eight lectures given at the C.I.M.E. session on “Vector bundles on curves. New directions ” held at Cetraro (Italy) in June 1995. The work presented here was done in collaboration with M.S. Narasimhan and A. Ramanathan and appeared in [KNR]. These notes differ from [KNR] in th ..."
Abstract

Cited by 57 (2 self)
 Add to MetaCart
These are notes for my eight lectures given at the C.I.M.E. session on “Vector bundles on curves. New directions ” held at Cetraro (Italy) in June 1995. The work presented here was done in collaboration with M.S. Narasimhan and A. Ramanathan and appeared in [KNR]. These notes differ from [KNR] in that we have
Equidistribution of small points, rational dynamics, and potential theory
 Ann. Inst. Fourier (Grenoble
, 2006
"... Abstract. Given a dynamical system associated to a rational function ϕ(T) on P 1 of degree at least 2 with coefficients in a number field k, we show that for each place v of k, there is a unique probability measure µϕ,v on the Berkovich space P 1 Berk,v /Cv such that if {zn} is a sequence of points ..."
Abstract

Cited by 25 (6 self)
 Add to MetaCart
Abstract. Given a dynamical system associated to a rational function ϕ(T) on P 1 of degree at least 2 with coefficients in a number field k, we show that for each place v of k, there is a unique probability measure µϕ,v on the Berkovich space P 1 Berk,v /Cv such that if {zn} is a sequence of points in P 1 (k) whose ϕcanonical heights tend to zero, then the zn’s and their Galois conjugates are equidistributed with respect to µϕ,v. In the archimedean case, µϕ,v coincides with the wellknown canonical measure associated to ϕ. This theorem generalizes a result of BakerHsia [BH] when ϕ(z) is a polynomial. The proof uses a polynomial lift F (x, y) = (F1(x, y), F2(x, y)) of ϕ to construct a twovariable ArakelovGreen’s function gϕ,v(x, y) for each v. The measure µϕ,v is obtained by taking the Berkovich space Laplacian of gϕ,v(x, y), using a theory developed in [RB]. The other ingredients in the proof are (i) a potentialtheoretic energy minimization principle which says that � � gϕ,v(x, y) dν(x)dν(y) is uniquely minimized over all probability measures ν on P 1 Berk,v when ν = µϕ,v, and (ii) a formula for homogeneous transfinite diameter of the vadic filled Julia set KF,v ⊂ C 2 v in terms of the resultant Res(F) of F1 and F2. The resultant formula, which generalizes a formula of DeMarco [DeM], is proved using results
Free Bosons and TauFunctions for Compact Riemann Surfaces and Closed Smooth Jordan Curves I. Current Correlation Functions
, 2001
"... We study families of quantum eld theories of free bosons on a compact Riemann surface of genus g. For the case g > 0 these theories are parameterized by holomorphic line bundles of degree g 1, and for the case g = 0  by smooth closed Jordan curves on the complex plane. In both cases we dene a noti ..."
Abstract

Cited by 13 (0 self)
 Add to MetaCart
We study families of quantum eld theories of free bosons on a compact Riemann surface of genus g. For the case g > 0 these theories are parameterized by holomorphic line bundles of degree g 1, and for the case g = 0  by smooth closed Jordan curves on the complex plane. In both cases we dene a notion of function as a partition function of the theory and evaluate it explicitly. For the case g > 0 the function is an analytic torsion [3], and for the case g = 0  the regularized energy of a certain natural pseudomeasure on the interior domain of a closed curve. For these cases we rigorously prove the Ward identities for the current correlation functions and determine them explicitly. For the case g > 0 these functions coincide with those obtained in [21, 36] using bosonization. For the case g = 0 the function we have dened coincides with the function introduced in [29, 44, 24] as a dispersionless limit of the Sato's function for the twodimensional Toda hierarchy. As a corollary of the Ward identities, we obtain recent results [44, 24] on relations between conformal maps of exterior domains and functions. For this case we also dene a Hermitian metric on the space of all contours of given area. As another corollary of the Ward identities we prove that the introduced metric is Kahler and the logarithm of the function is its Kahler potential. Contents
KTheory of topological algebras and second quantization, extended paper version of a homonymous talk delivered at the International Conference on Topological Algebras and Applications
 44 Mallios, A. and Raptis, I., Finitary Spacetime Sheaves of Quantum Causal Sets: Curving Quantum Causality, International Journal of Theoretical Physics
, 2001
"... Abstract. Applying the classical SerreSwan theorem, as this is extended to topological (nonnormed) algebras, one attains a classification of elementary particles via their spinstructure. In this context, our argument is virtually based on a “correspondence principle ” of S.A. Selesnick, formulate ..."
Abstract

Cited by 9 (5 self)
 Add to MetaCart
Abstract. Applying the classical SerreSwan theorem, as this is extended to topological (nonnormed) algebras, one attains a classification of elementary particles via their spinstructure. In this context, our argument is virtually based on a “correspondence principle ” of S.A. Selesnick, formulated herewith in a sheaftheoretic language, presisely speaking, in terms of vector sheaves. This then leads directly to second quantization, as well as, to other applications of geometric (pre)quantization theory. 0. Our aim by the present paper is to obtain a classification of elementary particles, that finally leads to a detour of the socalled first quantization and passage, instead, directly to “second quantization”, which, in effect, is the main point of “geometric (pre)quantization theory. Consequently, in that context, “to find a quantum model of... an elementary relativistic particle it is unnecessary... to quantize [first] the corresponding classical system”; see D.J. SimmsN.M.J. Woodhouse [26: p. 86]. This is actually in complete antithesis with what happens, classically. Indeed, in that case “... to quantize a field, we have first to describe it
From Dynamics on Surfaces to Rational Points on Curves
 BULLETIN AMS
, 1999
"... Introduction Fermat's last theorem states that for n 3 the equation X n + Y n = Z n (1.1) has no integer solutions with X;Y; Z 1. Inspiring generations of work in number theory, its proof was finally achieved by Wiles. A qualitative result, Finite Fermat, was obtained earlier by Faltings; ..."
Abstract

Cited by 8 (3 self)
 Add to MetaCart
Introduction Fermat's last theorem states that for n 3 the equation X n + Y n = Z n (1.1) has no integer solutions with X;Y; Z 1. Inspiring generations of work in number theory, its proof was finally achieved by Wiles. A qualitative result, Finite Fermat, was obtained earlier by Faltings; it says the Fermat equation has only a finite number of solutions (for each given n, up to rescaling). This paper is an appreciation of some of the topological intuitions behind number theory. It aims to trace a logical path from the classification of surface diffeomorphisms to the proof of Finite Fermat. The route we take is the following. x2. The isotopy classes of surface diffeomorphisms f : S ! S form the mapping class group Mod(S). Thurs
Models of Curves and Finite Covers
 COMPOSITIO MATHEMATICA
, 1999
"... Let K be a discrete valuation field with ring of integers OK.Letf: X → Y beafinite morphism of curves over K. In this article, we study some possible relationships between the models over OK of X and of Y. Three such relationships are listed below. Consider a Galois cover f: X → Y of degree prime t ..."
Abstract

Cited by 8 (1 self)
 Add to MetaCart
Let K be a discrete valuation field with ring of integers OK.Letf: X → Y beafinite morphism of curves over K. In this article, we study some possible relationships between the models over OK of X and of Y. Three such relationships are listed below. Consider a Galois cover f: X → Y of degree prime to the characteristic of the residue field, with branch locus B. We show that if Y has semistable reduction over K, thenX achieves semistable reduction over some explicit tame extension of K(B). When K is strictly henselian, we determine the minimal extension L/K with the property that XL has semistable reduction. Let f: X → Y be a finite morphism, with g(Y) � 2. We show that if X has a stable model X over OK, then Y has a stable model Y over OK, and the morphism f extends to a morphism X → Y. Finally, given any finite morphism f: X → Y, is it possible to choose suitable regular models X and Y of X and Y over OK such that f extends to a finite morphism X → Y? As was shown by Abhyankar, the answer is negative in general. We present counterexamples in rather general situations, with f a cyclic cover of any order � 4. On the other hand, we prove, without any hypotheses on the residual characteristic, that this extension problem has a positive solution when f is cyclic of order 2 or 3.
Hermitian vector bundles and extension groups on arithmetic schemes II. THE ARITHMETIC ATIYAH EXTENSION
, 2008
"... In a previous paper, we have defined arithmetic extension groups in the context of Arakelov geometry. In the present one, we introduce an arithmetic analogue of the Atiyah extension that defines an element — the arithmetic Atiyah class — in a suitable arithmetic extension group. Namely, if E is a ..."
Abstract

Cited by 7 (0 self)
 Add to MetaCart
In a previous paper, we have defined arithmetic extension groups in the context of Arakelov geometry. In the present one, we introduce an arithmetic analogue of the Atiyah extension that defines an element — the arithmetic Atiyah class — in a suitable arithmetic extension group. Namely, if E is a hermitian vector bundle on an arithmetic scheme X, its arithmetic Atiyah class bat X/Z(E) lies in the group d Ext 1 X(E, E ⊗ Ω1), and is an obstruction to the algebraicity over X of the X/Z unitary connection on the vector bundle EC over the complex manifold X(C) that is compatible with its holomorphic structure. In the first sections of this article, we develop the basic properties of the arithmetic Atiyah class which can be used to define characteristic classes in arithmetic Hodge cohomology. Then we study the vanishing of the first Chern class ĉH 1 (L) of a hermitian line bundle L in the arithmetic Hodge cohomology group d Ext 1
Arakelov Invariants of Riemann Surfaces
 DOCUMENTA MATH.
, 2005
"... We derive closed formulas for the ArakelovGreen function and the Faltings deltainvariant of a compact Riemann surface. ..."
Abstract

Cited by 7 (7 self)
 Add to MetaCart
We derive closed formulas for the ArakelovGreen function and the Faltings deltainvariant of a compact Riemann surface.
Dirichlet’s Theorem, Vojta’s Inequality, and Vojta’s Conjecture
, 1999
"... This paper addresses questions involving the sharpness of Vojta’s conjecture and Vojta’s inequality for algebraic points on curves over number fields. It is shown that one may choose the approximation term mS(D, −) in such a way that Vojta’s inequality is sharp in Theorem 2.3. Partial results are o ..."
Abstract

Cited by 6 (4 self)
 Add to MetaCart
This paper addresses questions involving the sharpness of Vojta’s conjecture and Vojta’s inequality for algebraic points on curves over number fields. It is shown that one may choose the approximation term mS(D, −) in such a way that Vojta’s inequality is sharp in Theorem 2.3. Partial results are obtained for the more difficult problem of showing that Vojta’s conjecture is sharp when the approximation term is not included (that is, when D = 0). In Theorem 3.7, it is demonstrated that Vojta’s conjecture is the best possible with D = 0 for quadratic points on hyperelliptic curves. It is also shown, in Theorem 4.8, that Vojta’s conjecture is sharp with D = 0 on a curve C over a number field when an analogous statement holds for the curve obtained by extending the base field of C to a certain function field.