17 research outputs found
Black Hole Attractor Varieties and Complex Multiplication
Black holes in string theory compactified on Calabi-Yau varieties a priori
might be expected to have moduli dependent features. For example the entropy of
the black hole might be expected to depend on the complex structure of the
manifold. This would be inconsistent with known properties of black holes.
Supersymmetric black holes appear to evade this inconsistency by having moduli
fields that flow to fixed points in the moduli space that depend only on the
charges of the black hole. Moore observed in the case of compactifications with
elliptic curve factors that these fixed points are arithmetic, corresponding to
curves with complex multiplication. The main goal of this talk is to explore
the possibility of generalizing such a characterization to Calabi-Yau varieties
with finite fundamental groups.Comment: 21 page
Scaling behavior of observables as a model characteristic in multifield inflation
One of the fundamental questions in inflation is how to characterize the
structure of different types of models in the field theoretic landscape.
Proposals in this direction include attempts to directly characterize the
formal structure of the theory by considering complexity measures of the
potentials. An alternative intrinsic approach is to focus on the behavior of
the observables that result from different models and to ask whether their
behavior differs among models. This type of analysis can be applied even to
nontrivial multifield theories where a natural measure of the complexity of the
model is not obvious and the analytical evaluation of the observables is often
impossible. In such cases one may still compute these observables numerically
and investigate their behavior. One interesting case is when observables show a
scaling behavior, in which case theories can be characterized in terms of their
scaling amplitudes and exponents. Generically, models have nontrivial parameter
spaces, leading to exponents that are functions of these parameters. In such
cases we consider an iterative procedure to determine whether the exponent
functions in turn lead to a scaling behavior. We show that modular inflation
models can be characterized by families of simple scaling laws and that the
scaling exponents that arise in this way in turn show a scaling law in
dependence of these varying energy scales.Comment: 20 pages, 6 figure
Landau-Ginzburg Vacua of String, M- and F-Theory at c=12
Theories in more than ten dimensions play an important role in understanding
nonperturbative aspects of string theory. Consistent compactifications of such
theories can be constructed via Calabi-Yau fourfolds. These models can be
analyzed particularly efficiently in the Landau-Ginzburg phase of the linear
sigma model, when available. In the present paper we focus on those sigma
models which have both a Landau-Ginzburg phase and a geometric phase described
by hypersurfaces in weighted projective five-space. We describe some of the
pertinent properties of these models, such as the cohomology, the connectivity
of the resulting moduli space, and mirror symmetry among the 1,100,055
configurations which we have constructed.Comment: LaTeX, 33 pages, 10 PostScript figures using epsfig and psfi
Observation and Properties of the X(3872) Decaying to J/ψπ+π− in p¯p Collisions at √s = 1.96 TeV
We report the observation of the X(3872) in the J/psi pi+pi- channel, with J/psi decaying to mu+mu- in p-p(bar) collisions at sqrt(s) = 1.96 TeV. Using approximately 230 pb^-1 of data collected with the Run II D0 detector, we observe 522 +/- 100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9 +/- 3.1 (stat.) +/- 3.0 (syst.) MeV/c^2. We have investigated the production and decay characteristics of the X(3872), and find them to be similar to those of the psi(2S) state
Unification of M- and F- Theory Calabi-Yau Fourfold Vacua
We consider splitting type phase transitions between Calabi-Yau fourfolds.
These transitions generalize previously known types of conifold transitions
between threefolds. Similar to conifold configurations the singular varieties
mediating the transitions between fourfolds connect moduli spaces of different
dimensions, describing ground states in M- and F-theory with different numbers
of massless modes as well as different numbers of cycles to wrap various
p-branes around. The web of Calabi-Yau fourfolds obtained in this way contains
the class of all complete intersection manifolds embedded in products of
ordinary projective spaces, but extends also to weighted configurations. It
follows from this that for some of the fourfold transitions vacua with
vanishing superpotential are connected to ground states with nonzero
superpotential.Comment: plain TeX, 22p
String Modular Phases in Calabi-Yau Families
We investigate the structure of singular Calabi-Yau varieties in moduli
spaces that contain a Brieskorn-Pham point. Our main tool is a construction of
families of deformed motives over the parameter space. We analyze these motives
for general fibers and explicitly compute the series for singular fibers
for several families. We find that the resulting motivic functions agree
with the series of modular forms whose weight depends both on the rank of
the motive and the degree of the degeneration of the variety. Surprisingly,
these motivic functions are identical in several cases to series
derived from weighted Fermat hypersurfaces. This shows that singular Calabi-Yau
spaces of non-conifold type can admit a string worldsheet interpretation, much
like rational theories, and that the corresponding irrational conformal field
theories inherit information from the Gepner conformal field theory of the
weighted Fermat fiber of the family. These results suggest that phase
transitions via non-conifold configurations are physically plausible. In the
case of severe degenerations we find a dimensional transmutation of the
motives. This suggests further that singular configurations with non-conifold
singularities may facilitate transitions between Calabi-Yau varieties of
different dimensions.Comment: 34 page
Complex Multiplication Symmetry of Black Hole Attractors
We show how Moore's observation, in the context of toroidal compactifications
in type IIB string theory, concerning the complex multiplication structure of
black hole attractor varieties, can be generalized to Calabi-Yau
compactifications with finite fundamental groups. This generalization leads to
an alternative general framework in terms of motives associated to a Calabi-Yau
variety in which it is possible to address the arithmetic nature of the
attractor varieties in a universal way via Deligne's period conjecture.Comment: 28 page
Geometric Kac-Moody Modularity
It is shown how the arithmetic structure of algebraic curves encoded in the Hasse-Weil L-function can be related to affine Kac-Moody algebras. This result is useful in relating the arithmetic geometry of Calabi-Yau varieties to the underlying exactly solvable theory. In the case of the genus three Fermat curve we identify the Hasse-Weil L-function with the Mellin transform of the twist of a number theoretic modular form derived from the string function of a non-twisted affine Lie algebra. The twist character is associated to the number field of quantum dimensions of the underlying conformal field theory