Papers by Justin Vazquez-poritz
It is shown that the curvature of spacetime, a possible net electric charge on the sun, a small p... more It is shown that the curvature of spacetime, a possible net electric charge on the sun, a small positive cosmological constant and the oblateness of the sun, in conjunction with solar radiation pressure (SPR), affect the bound orbital motion of solar sails and lead to deviations from Kepler's third law for heliocentric and non-Keplerian orbits. With regards to the Lense-Thirring effect, the SRP increases the amount of precession per orbit for polar orbits. Non-Keplerian polar orbits exhibit an analog of the Lense-Thirring effect in which the orbital plane precesses around the sun.
We find that the drag force for a heavy quark moving through N=4 SU(N_c) supersymmetric Yang-Mill... more We find that the drag force for a heavy quark moving through N=4 SU(N_c) supersymmetric Yang-Mills plasma is generally enhanced by the leading correction due to finite 't Hooft coupling. For a bottom quark, the drag force increases by about 50%, whereas for a charm quark it increases by about 5%. We also discuss the drag force for the case of Gauss-Bonnet gravity.
Journal of High Energy Physics, 2001
The absorption in the extremal D3-brane background is studied for a class of massless fields whos... more The absorption in the extremal D3-brane background is studied for a class of massless fields whose linear perturbations leave the ten-dimensional background metric unperturbed, as well as the minimally-coupled massive scalar. We find that various fields have the same absorption probability as that of the dilaton-axion system, which is given exactly via the Mathieu equation. We analyze the features of the absorption cross-sections in terms of effective Schrödinger potentials, conjecture a general form of the dual effective potentials, and provide explicit numerical results for the whole energy range. As expected, all partial-wave absorption probabilities tend to zero (one) at low (large) energies, and exhibit an oscillatory pattern as a function of energy. The equivalence of absorption probabilities for various modes has implications for the correlation functions on the field, including subleading contributions on the field-theory side. In particular, certain half-integer and integer spin fields have identical absorption probabilities, thus providing evidence that the corresponding operator pairs on the field theory side belong to the same supermultiplets.
We consider the behavior of open strings on AdS wormholes in Gauss-Bonnet theory, which are the G... more We consider the behavior of open strings on AdS wormholes in Gauss-Bonnet theory, which are the Gauss-Bonnet gravity duals of a pair of field theories. A string with both endpoints on the same side of the wormhole describes two charges within the same field theory, which exhibit Coulomb interaction for small separation. On the other hand, a string extending through the wormhole describes two charges which live in different field theories, and they exhibit a spring-like confining potential. A transition occurs when there is a pair of charges present within each field theory: for small separation each pair of charges exhibits Coulomb interaction, while for large separation the charges in the different field theories pair up and exhibit confinement. If two charges move faster than a critical speed, then they exhibit a separation gap and energy is transferred from the leading charge to the lagging one.
Classical and Quantum Gravity, 2006
We consider supersymmetric SL(3,R) deformations of various type IIB supergravity backgrounds whic... more We consider supersymmetric SL(3,R) deformations of various type IIB supergravity backgrounds which exhibit flows away from an asymptotically locally AdS_5 x S^5 fixed point. This includes the gravity dual of the Coulomb branch of N=1 super Yang Mills theory, for which the deformed superpotential is known. We also consider the gravity duals of field theories which live on various curved backgrounds, such as Minkowski_2 x H^2, AdS_3 x S^1 and R x S^3. Some of the deformed theories flow from a four-dimensional N=1 superconformal UV fixed point to a two-dimensional (2,2) superconformal IR fixed point. We study nonsupersymmetric generalizations of the deformations of the above Coulomb branch flows.
Small black holes potentially created by the Large Hadron Collider could typically carry color ch... more Small black holes potentially created by the Large Hadron Collider could typically carry color charges inherited from their parton progenitors. The dynamics of quarks near such a black hole depends on the curved spacetime geometry as well as the strong interaction due to the color charge of the black hole. We use the AdS/CFT Correspondence to study the behavior of strongly-coupled quarks near a color-charged black hole. The supergravity background consists of a six-dimensional Schwarzschild-black string AdS soliton, for which the bulk horizon extends from the AdS boundary down to an infra-red floor. By going to higher energy scales, the regime of validity of the classical supergravity background can be extended closer to the singularity than might be expected from the four-dimensional perspective. We study the resulting behavior of quarks and compute the rate at which a quark rotating around the black hole loses energy as a function of its mass parameter and angular velocity. We also analyze the behavior of quark-antiquark string configurations and discuss features such as the quark-antiquark screening length.
Journal of High Energy Physics, 2006
We consider type IIB supergravity backgrounds which describe marginal deformations of the Coulomb... more We consider type IIB supergravity backgrounds which describe marginal deformations of the Coulomb branch of N=4 super Yang-Mills theory with SO(4) x SO(2) global symmetry. Wilson loop calculations indicate that certain deformations enhance the Coulombic attraction between quarks and anti-quarks at the UV conformal fixed-point. In the IR region, these deformations can induce a transition to linear confinement.
A recently proposed holographic duality allows the Bekenstein-Hawking entropy of extremal rotatin... more A recently proposed holographic duality allows the Bekenstein-Hawking entropy of extremal rotating black holes to be calculated microscopically, by applying the Cardy formula to the two-dimensional chiral CFTs associated with certain reparameterisations of azimuthal angular coordinates in the solutions. The central charges are proportional to the angular momenta of the black hole, and so the method degenerates in the case of static (non-rotating) black holes. We show that the method can be extended to encompass such charged static extremal AdS black holes by using consistent Kaluza-Klein sphere reduction ansätze to lift them to exact solutions in the low-energy limits of string theory or M-theory, where the electric charges become reinterpreted as angular momenta associated with internal rotations in the reduction sphere. We illustrate the procedure for the examples of extremal charged static AdS black holes in four, five, six and seven dimensions.
Physical Review D, 2009
[hep-th] for the gravity dual of an open Wilson line in the Sakai-Sugimoto model or its non-compa... more [hep-th] for the gravity dual of an open Wilson line in the Sakai-Sugimoto model or its non-compact version. In particular, we use their proposal to determine the effect of finite temperature, as well as background electric and magnetic fields, on the chiral symmetry breaking order parameter. We also generalize their prescription to more complicated worldsheets and identify the operators dual to such worldsheets.
It is shown that the curvature of spacetime, a possible net electric charge on the sun, a small p... more It is shown that the curvature of spacetime, a possible net electric charge on the sun, a small positive cosmological constant and the oblateness of the sun, in conjunction with solar radiation pressure (SPR), affect the bound orbital motion of solar sails and lead to deviations from Kepler's third law for heliocentric and non-Keplerian orbits. With regards to the Lense-Thirring effect, the SRP increases the amount of precession per orbit for polar orbits. Non-Keplerian polar orbits exhibit an analog of the Lense-Thirring effect in which the orbital plane precesses around the sun.
For a brane world embedded in various ten or eleven-dimensional geometries, we calculate the corr... more For a brane world embedded in various ten or eleven-dimensional geometries, we calculate the corrections to the four-dimensional gravitational potential due to graviton modes propagating in the extra dimensions, including those rotating around compact directions. Due to additional "warp" factors, these rotation modes may have as significant an effect as the s-wave modes which propagate in the large or infinite extra dimension.
Nuclear Physics B - NUCL PHYS B, 2005
We show that AdS black hole solutions admit an analytical continuation to become magnetic flux-br... more We show that AdS black hole solutions admit an analytical continuation to become magnetic flux-branes. Although a static BPS AdS black hole generally has a naked singularity, the BPS flux-brane can be regular everywhere with an appropriate choice of U(1)U(1)-charges. This flux-brane interpolates from AdSD−2×H2AdSD−2×H2 at small distance to an asymptotic AdSDAdSD-type metric with an AdSD−2×S1AdSD−2×S1 boundary. We also obtain a smooth cosmological solution of de Sitter Einstein–Maxwell gravity which flows from dS2×SD−2dS2×SD−2 in the infinite past to a dSDdSD-type metric, with an SD−2×S1SD−2×S1 boundary, in the infinite future.
Physics Letters B, 2003
We obtain smooth M-theory solutions whose geometry is a warped product of AdS 5 and a compact int... more We obtain smooth M-theory solutions whose geometry is a warped product of AdS 5 and a compact internal space that can be viewed as an S 4 bundle over S 2 . The bundle can be trivial or twisted, depending on the even or odd values of the two diagonal monopole charges. The solution preserves N = 2 supersymmetry and is dual to an N = 1 D = 4 superconformal field theory, providing a concrete framework to study the AdS 5 /CFT 4 correspondence in M-theory. We construct analogous embeddings of AdS 4 , AdS 3 and AdS 2 in massive type IIA, type IIB and M-theory, respectively. The internal spaces have generalized holonomy and can be viewed as S n bundles over S 2 for n = 4, 5 and 7. Surprisingly, the dimensions of spaces with generalized holonomy includes D = 9. We also obtain a large class of solutions of AdS×H 2 .
Nuclear Physics B, 2004
We investigate a large class of supersymmetric magnetic brane solutions supported by U(1) gauge f... more We investigate a large class of supersymmetric magnetic brane solutions supported by U(1) gauge fields in AdS gauged supergravities. We obtain first-order equations in terms of a superpotential. In particular, we find systems which interpolate between AdS D−2 × Ω 2 (where Ω 2 = S 2 or H 2 ) at the horizon and AdS D -type geometry in the asymptotic region, for 4 ≤ D ≤ 7. The boundary geometry of the AdS D -type metric is Minkowski D−3 × Ω 2 . This provides smooth supergravity solutions for which the boundary of the AdS spacetime compactifies spontaneously. These solutions indicate the existence of a large class of superconformal field theories in diverse dimensions whose renormalization group flow runs from the UV to the IR fixed-point. We show that the same set of first-order equations also admits solutions which are asymptotically AdS D−2 × Ω 2 but singular at small distance. This implies that the stationary AdS D−2 × Ω 2 solutions typically lie on the inflection points of the modulus space.
Physical Review D - PHYS REV D, 2000
We obtain a large class of AdS spacetimes warped with certain internal spaces in eleven-dimension... more We obtain a large class of AdS spacetimes warped with certain internal spaces in eleven-dimensional and type IIA/IIB supergravities. The warp factors depend only on the internal coordinates. These solutions arise as the near-horizon geometries of more general semi-localised multi-intersections of $p$-branes. We achieve this by noting that any sphere (or AdS spacetime) of dimension greater than 3 can be viewed as a foliation involving S^3 (or AdS_3). Then the S^3 (or AdS_3) can be replaced by a three-dimensional lens space (or a BTZ black hole), which arises naturally from the introduction of a NUT (or a pp-wave) to the M-branes or the D3-brane. We then obtain multi-intersections by performing a Kaluza-Klein reduction or Hopf T-duality transformation on the fibre coordinate of the lens space (or the BTZ black hole). These geometries provide further possible examples of the AdS/CFT correspondence and of consistent embeddings of lower-dimensional gauged supergravities in D=11 or D=10.
Physics Letters B - PHYS LETT B, 2009
General relativity can have a significant impact on the long-range escape trajectories of solar s... more General relativity can have a significant impact on the long-range escape trajectories of solar sails deployed near the sun. For example, spacetime curvature in the vicinity of the sun can cause a solar sail traveling from about 4 solar radii to 2550 AU to be deflected by on the order of a million kilometers, and should therefore be taken into account at the beginning of the mission. There are a number of smaller general relativistic effects, such as frame dragging due to the slow rotation of the sun which can cause a deflection of more than one thousand kilometers.
A number of recent papers have applied the AdS/CFT correspondence to a strong-coupling calculatio... more A number of recent papers have applied the AdS/CFT correspondence to a strong-coupling calculation of the medium-induced radiative parton energy loss in nucleus-nucleus collisions at RHIC. The predicted value of the "jet quenching parameter" q, however, is rather small compared to the experimental results. For hot N=4 supersymmetric Yang-Mills theory, certain marginal deformations can have the effect of enhancing q. This result is highly sensitive to the location of the fundamental string's endpoints in the internal space.
Nuclear Physics B, 2007
We discuss D3-branes on cohomogeneity-three resolved Calabi–Yau cones over LabcLabc spaces, for w... more We discuss D3-branes on cohomogeneity-three resolved Calabi–Yau cones over LabcLabc spaces, for which a 2-cycle or 4-cycle has been blown up. In terms of the dual quiver gauge theory, this corresponds to motion along the non-mesonic, or baryonic, directions in the moduli space of vacua. In particular, a dimension-two and/or dimension-six scalar operator gets a vacuum expectation value. These resolved cones support various harmonic (2,1)(2,1)-forms which reduce the ranks of some of the gauge groups either by a Seiberg duality cascade or by Higgsing. We also discuss higher-dimensional resolved Calabi–Yau cones. In particular, we obtain square-integrable (2,2)(2,2)-forms for eight-dimensional cohomogeneity-four Calabi–Yau metrics.
Classical and Quantum Gravity, 2005
We construct deformed, T 2 -wrapped, rotating M2-branes on a resolved cone over as well as on a p... more We construct deformed, T 2 -wrapped, rotating M2-branes on a resolved cone over as well as on a product of two Eguchi-Hanson instantons. All worldvolume directions of these supersymmetric and regular solutions are fibred over the transverse space. These constitute gravity duals of D = 3 N = 2 gauge theories.
We study general relativistic effects on the bound orbits of solar sails. The combined effects of... more We study general relativistic effects on the bound orbits of solar sails. The combined effects of spacetime curvature and solar radiation
pressure (SRP) lead to deviations from Kepler’s third law. Such kind of deviations also arise from frame dragging, the gravitational multipole
moments of the sun, a net electric charge on the sun, and a positive cosmological constant. The SRP increases these deviations by
several orders of magnitude, possibly rendering some of them detectable. We consider how the SRP modifies the perihelion shift of noncircular
orbits, as well as the Lense-Thirring effect involving the precession of polar orbits. We investigate how the pitch angle for non-
Keplerian orbits changes due to the partial absorption of light, general relativistic effects, and the oblateness of the sun. It is predicted
that there is an analog of the Lense-Thirring effect for non-Keplerian orbits, in that the orbital plane precesses around the sun. We also
consider the Poynting–Robertson effect and show that this effect can, in principle, be compensated for by an extremely small tilt of the
solar sail.
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Papers by Justin Vazquez-poritz
pressure (SRP) lead to deviations from Kepler’s third law. Such kind of deviations also arise from frame dragging, the gravitational multipole
moments of the sun, a net electric charge on the sun, and a positive cosmological constant. The SRP increases these deviations by
several orders of magnitude, possibly rendering some of them detectable. We consider how the SRP modifies the perihelion shift of noncircular
orbits, as well as the Lense-Thirring effect involving the precession of polar orbits. We investigate how the pitch angle for non-
Keplerian orbits changes due to the partial absorption of light, general relativistic effects, and the oblateness of the sun. It is predicted
that there is an analog of the Lense-Thirring effect for non-Keplerian orbits, in that the orbital plane precesses around the sun. We also
consider the Poynting–Robertson effect and show that this effect can, in principle, be compensated for by an extremely small tilt of the
solar sail.
pressure (SRP) lead to deviations from Kepler’s third law. Such kind of deviations also arise from frame dragging, the gravitational multipole
moments of the sun, a net electric charge on the sun, and a positive cosmological constant. The SRP increases these deviations by
several orders of magnitude, possibly rendering some of them detectable. We consider how the SRP modifies the perihelion shift of noncircular
orbits, as well as the Lense-Thirring effect involving the precession of polar orbits. We investigate how the pitch angle for non-
Keplerian orbits changes due to the partial absorption of light, general relativistic effects, and the oblateness of the sun. It is predicted
that there is an analog of the Lense-Thirring effect for non-Keplerian orbits, in that the orbital plane precesses around the sun. We also
consider the Poynting–Robertson effect and show that this effect can, in principle, be compensated for by an extremely small tilt of the
solar sail.