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C. Gomez

Publications and source records attributed to C. Gomez.

At least 37 records · Page 2Linked to original sources
arXiv2008

The Quijote CMB Experiment

We present the current status of the QUIJOTE (Q-U-I JOint TEnerife) CMB Experiment, a new instrument which will start operations early 2009 at Teide Observatory, with the aim of characterizing the polarization of the CMB and other processes of galactic and extragalactic emission in the frequency range 10-30 GHz and at large angular scales. QUIJOTE will be a valuable complement at low frequencies for the PLANCK mission, and will have the required sensitivity to detect a primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r=0.05.

astro-ph↗
arXiv2007

Gluon Saturation and Black Hole Criticality

We discuss the recent proposal in hep-th/0611312 where it was shown that the critical anomalous dimension associated to the onset of non-linear effects in the high energy limit of QCD coincides with the critical exponent governing the radius of the black hole formed in the spherically symmetric collapse of a massless scalar field. We argue that a new essential ingredient in this mapping between gauge theory and gravity is continuous self-similarity, not present in the scalar field case but in the spherical collapse of a perfect fluid with barotropic equation of state. We identify this property with geometric scaling, present in DIS data at small values of Bjorken x. We also show that the Choptuik exponent in dimension five tends to the QCD critical value in the traceless limit of the energy momentum tensor.

hep-th↗
arXiv2000

Non-Critical Poincaré Invariant Bosonic String Backgrounds and Closed String Tachyons

A new family of non critical bosonic string backgrounds in arbitrary space time dimension $D$ and with $ISO(1,D-2)$ Poincaré invariance are presented. The metric warping factor and dilaton agree asymptotically with the linear dilaton background. The closed string tachyon equation of motion enjoys, in the linear approximation, an exact solution of ``kink'' type interpolating between different expectation values. A renormalization group flow interpretation ,based on a closed string tachyon potential of type $-T^{2}e^{-T}$, is suggested.

hep-th↗
arXiv2000

Holography and the C-Theorem

We review the geometric definition of C-function in the context of field theories that admit a holographic gravity dual.

hep-th↗
arXiv2000

A Comment on Fisher Information and Quantum Algorithms

We show that Grover's algorithm defines a geodesic in quantum Hilbert space with the Fubini-Study metric. From statistical point of view Grover's algorithm is characterized by constant Fisher's function. Quantum algorithms changing complexity class as Shor's factorization does not preserve constant Fisher's information. An adiabatic quantum factorization algorithm in non polynomial time is presented to exemplify the result.

quant-ph↗
arXiv1999

Non-Critical Confining Strings and the Renormalization Group

String vacua for non critical strings satisfying the requirements of Zig-Zag invariance are constructed. The Liouville mode is shown to play the rôle of scale in the Renormalization Group operation. Differences and similarities with the D-brane near horizon approach to non supersymmetric gauge theories are discussed as well.

hep-th↗
arXiv1998

String Representation of Wilson Loops

We explore the consequences of imposing Polyakov's zig/zag-invariance in the search for a confining string. We first find that the requirement of zig/zag-invariance seems to be incompatible with spacetime supersymmetry. We then try to find zig/zag-invariant string backgrounds on which to implement the minimal-area prescription for the calculation of Wilson loops considering different possibilities.

hep-th↗
arXiv1997

Fields, Strings and Branes

Lecture notes reviewing most recent developments in string/M/brane theory given by C. G. at the CIME Summer International Center of Mathematics at Cetraro. July 1997.

hep-th↗
arXiv1996

$K3$-Fibrations and Softly Broken $N=4$ Supersymmetric Gauge Theories

Global geometry of $K3$-fibration Calabi-Yau threefolds, with Hodge number $h_{2,1}=r+1$, is used to define $N=4$ softly broken $SU(r+1)$ gauge theories, with the bare coupling constant given by the dual heterotic dilaton, and the mass of the adjoint hypermultiplet given by the heterotic string tension. The $U(r+1)$ Donagi-Witten integrable model is also derived from the $K3$-fibration structure, with the extra $U(1)$ associated to the heterotic dilaton. The case of $SU(2)$ gauge group is analyzed in detail. String physics beyond the heterotic point particle limit is partially described by the $N=4$ softly broken theory.

hep-th↗
arXiv1996

Integrability, Jacobians and Calabi-Yau Threefolds

The integrable systems associated with Seiberg-Witten geometry are considered both from the Hitchin-Donagi-Witten gauge model and in terms of intermediate Jacobians of Calabi-Yau threefolds. Dual pairs and enhancement of gauge symmetries are discussed on the basis of a map from the Donagi-Witten ``moduli'' into the moduli of complex structures of the Calabi-Yau threefold.

hep-th↗
arXiv1996

Integrability, Duality and Strings

In these notes evidence is presented for intepreting the moduli space of the integrable model associated to $N\!=\!2$ gauge theories with $N\!=\!4$ matter content, in terms of Calabi-Yau manifolds. We restrict to the case of gauge group $SU(2)$, which is compared with the moduli space of the Calabi-Yau manifold $WP_{11226}^{12}$ appearing in the rank three dual pair $(K^{3}\times T^{2} / WP_{11226}^{12})$. The singularity loci of both spaces are maped in a one to one way and, in the weak coupling limit, $N\!=\!2$ $SU(2)$ pure Yang-Mills is obtained in both cases by the same type of blow up. Comments on the interpretation of the strong coupling locus from the perspective of the integrable system are done.

hep-th↗
arXiv1996

$S$-Duality and the Calabi-Yau Interpretation of the $N = 4$ to $N = 2$ Flow

The action of the $S$-duality $Sl(2,Z)$ group on the moduli of the Calabi-Yau manifold $W\IP^{12}_{11226}$ appearing in the rank two dual pair $(K^{3}\times T^{2}/W\IP^{12}_{11226})$ is defined by interpreting the $N\!=\!4$ to $N\!=\!2$ flow, for $SU(2)$ supersymmetric Yang-Mills, in terms of the Calabi-Yau moduli. The different singularity loci are mapped in a one to one way, and the ($N\!=\!2$ limit/point particle limit) is obtained in both cases by the same type of blow up. Moreover, it is shown that the $S$-duality group permutes the different singularity loci of the moduli of $W\IP^{12}_{11226}$. We study the transformation under $S$-duality of the Calabi-Yau Yukawa couplings.

hep-th↗
arXiv1995

A Note on the String Analog of $N=2$ Super-Symmetric Yang-Mills

A connection between the conifold locus of the type II string on the $W\:P_{11226}^4$ Calabi-Yau manifold and the geometry of the quantum moduli of $N = 2$ $SU(2)$ super Yang-Mills is presented. This relation is obtained from the anomalous behaviour of the $SU(2)$ super Yang-Mills special coordinates under $S$-duality transformation in $Sl(2;Z) / Γ_2$.

hep-th↗
arXiv1995

From Quantum Monodromy to Duality

For $N\!=\!2$ SUSY theories with non-vanishing $β$-function and one-dimensional quantum moduli, we study the representation on the special coordinates of the group of motions on the quantum moduli defined by $Γ_W\!=\!Sl(2;Z)\!/\!Γ_M$, with $Γ_M$ the quantum monodromy group. $Γ_W$ contains both the global symmetries and the strong-weak coupling duality. The action of $Γ_W$ on the special coordinates is not part of the symplectic group $Sl(2;Z)$. After coupling to gravity, namely in the context of non-rigid special geometry, we can define the action of $Γ_W$ as part of $Sp(4;Z)$. To do this requires singular gauge transformations on the "scalar" component of the graviphoton field. In terms of these singular gauge transformations the topological obstruction to strong-weak duality can be interpreted as a $σ$-model anomaly, indicating the possible dynamical role of the dilaton field in $S$-duality.

hep-th↗
arXiv1995

On the String Interpretation of the $t{\bar t}$-geometry

We derive the $t{\bar t}$-equations for generic $N\!=\!2$ topological field theories as consistency conditions for the contact term algebra of topological strings. A generalization of the holomorphic anomaly equation, known for the critical ${\hat c}\!=\!3$ case, to arbitrary non critical topological strings is presented. The interplay between the non trivial cohomology of the $b$-antighost, gravitational descendants and $\bar t$-dependence is discussed. The physical picture emerging from this study is that the $\bar t$ (background) dependence of topological strings with non trivial cohomology for the $b$-antighost, is determined by gravitational descendants.

hep-th↗
arXiv1994

Topology and Strings: Topics in $N=2$

A review on topological strings and the geometry of the space of two dimensional theories. (Lectures given by C. Gomez at the Enrico Fermi Summer School, Varenna, July 1994)

hep-th↗