67 research outputs found
Topological Amplitudes in Heterotic Strings with Wilson Lines
We consider d=4, N=2 compactifications of heterotic strings with an arbitrary number of Wilson lines. In particular, we focus on known chains of candidate heterotic/type II duals. We give closed expressions for the topological amplitudes F^g in terms of automorphic forms of SO(2+k,2,Z), and find agreement with the geometric data of the dual K3 fibrations wherever those are known
Nonperturbative Effects and the Large-Order Behavior of Matrix Models and Topological Strings
This work addresses nonperturbative effects in both matrix models and
topological strings, and their relation with the large-order behavior of the
1/N expansion. We study instanton configurations in generic one-cut matrix
models, obtaining explicit results for the one-instanton amplitude at both one
and two loops. The holographic description of topological strings in terms of
matrix models implies that our nonperturbative results also apply to
topological strings on toric Calabi-Yau manifolds. This yields very precise
predictions for the large-order behavior of the perturbative genus expansion,
both in conventional matrix models and in topological string theory. We test
these predictions in detail in various examples, including the quartic matrix
model, topological strings on the local curve, and Hurwitz theory. In all these
cases we provide extensive numerical checks which heavily support our
nonperturbative analytical results. Moreover, since all these models have a
critical point describing two-dimensional gravity, we also obtain in this way
the large-order asymptotics of the relevant solution to the Painleve I
equation, including corrections in inverse genus. From a mathematical point of
view, our results predict the large-genus asymptotics of simple Hurwitz numbers
and of local Gromov-Witten invariants.Comment: 50 pages, 24 figures, JHEP3.cls; v2: added references, added
discussion on Painleve I, final version for CNT
Multi-Instantons and Multi-Cuts
We discuss various aspects of multi-instanton configurations in generic
multi-cut matrix models. Explicit formulae are presented in the two-cut case
and, in particular, we obtain general formulae for multi-instanton amplitudes
in the one-cut matrix model case as a degeneration of the two-cut case. These
formulae show that the instanton gas is ultra-dilute, due to the repulsion
among the matrix model eigenvalues. We exemplify and test our general results
in the cubic matrix model, where multi-instanton amplitudes can be also
computed with orthogonal polynomials. As an application, we derive general
expressions for multi-instanton contributions in two-dimensional quantum
gravity, verifying them by computing the instanton corrections to the string
equation. The resulting amplitudes can be interpreted as regularized partition
functions for multiple ZZ-branes, which take into full account their
back-reaction on the target geometry. Finally, we also derive structural
properties of the trans-series solution to the Painleve I equation.Comment: 34 pages, 3 figures, JHEP3.cls; v2: added references, minor changes;
v3: added 1 reference, more minor changes, final version for JMP; v4: more
typos correcte
Direct Integration of the Topological String
We present a new method to solve the holomorphic anomaly equations governing
the free energies of type B topological strings. The method is based on direct
integration with respect to the non-holomorphic dependence of the amplitudes,
and relies on the interplay between non-holomorphicity and modularity
properties of the topological string amplitudes. We develop a formalism valid
for any Calabi-Yau manifold and we study in detail two examples, providing
closed expressions for the amplitudes at low genus, as well as a discussion of
the boundary conditions that fix the holomorphic ambiguity. The first example
is the non-compact Calabi-Yau underlying Seiberg-Witten theory and its
gravitational corrections. The second example is the Enriques Calabi-Yau, which
we solve in full generality up to genus six. We discuss various aspects of this
model: we obtain a new method to generate holomorphic automorphic forms on the
Enriques moduli space, we write down a new product formula for the fiber
amplitudes at all genus, and we analyze in detail the field theory limit. This
allows us to uncover the modularity properties of SU(2), N=2 super Yang-Mills
theory with four massless hypermultiplets.Comment: 75 pages, 3 figure
Genetic Regulation of Platelet Receptor Expression and Function: Application in Clinical Practice and Drug Development
Understanding genetic contributions to platelet function could have profound clinical ramifications for personalizing platelet-directed pharmacotherapy, by providing insight into the risks and possible benefits associated with specific genotypes. This article represents an integrated summary of presentations related to genetic regulation of platelet receptor expression and function given at the Fifth Annual Platelet Colloquium in January 2010. It is supplemented with additional highlights from the literature covering 1) approaches to determining and evidence for the associations of genetic variants with platelet hypo- and hyperresponsive phenotypes, 2) the ramifications of these polymorphisms with regard to clinical responses to antiplatelet therapies, and 3) the role of platelet function/genetic testing in guiding antiplatelet therapy
The management of desmoid tumours: A joint global consensus-based guideline approach for adult and paediatric patients
Abstract Desmoid tumor (DT; other synonymously used terms: Desmoid-type fibromatosis, aggressive fibromatosis) is a rare and locally aggressive monoclonal, fibroblastic proliferation characterised by a variable and often unpredictable clinical course. Previously surgery was the standard primary treatment modality; however, in recent years a paradigm shift towards a more conservative management has been introduced and an effort to harmonise the strategy amongst clinicians has been made. We present herein an evidence-based, joint global consensus guideline approach to the management of this disease focussing on: molecular genetics, indications for an active treatment, and available systemic therapeutic options. This paper follows a one-day consensus meeting held in Milan, Italy, in June 2018 under the auspices of the European Reference Network for rare solid adult cancers, EURACAN, the European Organisation for Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group (STBSG) as well as Sarcoma Patients EuroNet (SPAEN) and The Desmoid tumour Research Foundation (DTRF). The meeting brought together over 50 adult and pediatric sarcoma experts from different disciplines, patients and patient advocates from Europe, North America and Japan
Consortium neuroscience of attention deficit/hyperactivity disorder and autism spectrum disorder:The ENIGMA adventure
International audienc
Factors related to HPV vaccine uptake and 3-dose completion among women in a low vaccination region of the USA: an observational study
On the issue of transparency and reproducibility in nanomedicine.
Following our call to join in the discussion over the suitability of implementing a reporting checklist for bio-nano papers, the community responds
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