Haut PDF Loop corrections to the antibrane potential

Loop corrections to the antibrane potential

Loop corrections to the antibrane potential

CEA, CNRS, F-91191 Gif sur Yvette, France iosif.bena, johan.blaback, david.turton @ cea.fr Abstract Antibranes provide some of the most generic ways to uplift Anti-de Sitter flux compactifications to de Sitter, and there is a growing body of evidence that antibranes placed in long warped throats such as the Klebanov-Strassler warped deformed conifold solution have a brane-brane-repelling tachyon. This tachyon was first found in the regime of parameters in which the backreaction of the antibranes is large, and its existence was inferred from a highly nontriv- ial cancellation of certain terms in the inter-brane potential. We use a brane effective action approach, similar to that proposed by Michel, Mintun, Polchin- ski, Puhm and Saad in arXiv:1412.5702, to analyze antibranes in Klebanov- Strassler when their backreaction is small, and find a regime of parameters where all perturbative contributions to the action can be computed explicitly. We find that the cancellation found at strong coupling is also present in the weak-coupling regime, and we establish its existence to all loops. Our cal- culation indicates that the spectrum of the antibrane worldvolume theory is not gapped, and may generically have a tachyon. Hence uplifting mechanisms involving antibranes remain questionable even when backreaction is small.
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Leading two-loop corrections to the Higgs boson masses in SUSY models with Dirac gauginos

Leading two-loop corrections to the Higgs boson masses in SUSY models with Dirac gauginos

with respect to the top Yukawa coupling. Our purpose here is to elucidate the dependence of the corrections to the SM-like Higgs boson mass m h on relevant parameters such as the stop masses and mixing and the gluino masses, rather than provide accurate predictions for all Higgs boson masses in realistic scenarios. We therefore approximate the one-loop part of the corrections with the dominant top/stop contributions at vanishing external momentum, obtained by combining the formulae for the Higgs mass matrices given for MDGSSM and MRSSM in sections 3.3 and 3.4 , respectively, with the one-loop functions given in eq. ( 3.59 ). We recall that a computation of the Higgs boson masses in models with Dirac gauginos could also be obtained in an automated way by means of the package SARAH [ 51 – 56 ]. That would include the full one-loop corrections [ 54 ] and the two-loop corrections computed in the gaugeless limit at vanishing external momentum [ 57 , 58 ]. However, the computation implemented in SARAH employs the DR renormalisation scheme, and does not easily lend itself to an adaptation to the OS scheme which, as discussed in section 3.7.2 , can be more appropriate in scenarios with heavy gluinos.
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Two-loop QCD corrections to the MSSM Higgs masses beyond the effective-potential approximation

Two-loop QCD corrections to the MSSM Higgs masses beyond the effective-potential approximation

The predictions for the lightest-scalar mass, as obtained from popular codes for the determination of the MSSM mass spectrum, carry a theoretical uncertainty that has been esti- mated to be (at least) of the order of ±3 GeV – see, e.g., Refs. [ 78 , 79 ] and the more recent discussion in Ref. [ 82 ]. Against this backdrop, the corrections presented in this paper can be considered sub-dominant, and their inclusion in pub- lic codes might seem less urgent than, e.g., the inclusion of the dominant three-loop effects [ 41 , 42 ] or the proper resum- mation of large logarithms in scenarios with multi-TeV stop masses [ 39 , 40 , 82 ], both of which can shift the prediction for the lightest-scalar mass by several GeV. Nevertheless, one should not forget that the accuracy of the measurement of the Higgs mass at the LHC has already reached the level of a few hundred MeV – i.e., comparable to our sub-dominant cor- rections – and will improve further when more data become available. If SUSY shows up at last when the LHC operates at 13–14 TeV, the Higgs mass will serve as a precision observ- able to constrain MSSM parameters that might not be directly accessible by experiment. To this purpose, the accuracy of the theoretical prediction will have to match the experimen- tal one, making a full inclusion of the two-loop corrections to the Higgs masses unavoidable. Our calculation should be regarded as a necessary step in that direction.
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Dynamical relativistic corrections to the leptonic decay width of heavy quarkonia

Dynamical relativistic corrections to the leptonic decay width of heavy quarkonia

In order to get an agreement with the experimental decay width, the square of the wave function at the origin needs to be of the order of 6 to 8 GeV 3 . This has several interesting consequences. On the one hand, two potentials which are compatible with the J/Ψ decay width (logarithmic [14], and power law [13]) give a far too small decay width for the Υ [17]. These potentials have no Coulombic components, and they lack in high momentum components which show up in the Υ sector. On the other hand, a pure Coulombic potential still gives a too large wave function at the origin. The two potentials of Refs. [12, 15], which correct the Coulomb interaction at short distances according to asymptotic freedom, are compatible with the experimental Υ decay width 3 , as well as the J/Ψ one.
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Supersymmetric R$^4$ actions and quantum corrections to superspace torsion constraints

Supersymmetric R$^4$ actions and quantum corrections to superspace torsion constraints

it is tempting to make the following substitution in the super-Maxwell action: F r 1 r 2 → R r 1 r 2 s 1 s 2 , χ → ψ s 1 s 2 , D r χ → D r ψ s 1 s 2 , (10) Unfortunately, the difference in structure between the equations of motion for the gauge potential and the spin connection implies that the previous mapping does not commute with supersymmetry, as can be seen by the presence of the second line in the supersymmetry transformation of the Riemann tensor above. Another crucial difference between the super-Maxwell and supergravity cases is that, when subtracting all the lowest-order equations of motions, it is necessary to make the following substitution for the Riemann tensor:
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Corrections to "Geometric Properties of Gradient Projection Anti-windup Compensated Systems"

Corrections to "Geometric Properties of Gradient Projection Anti-windup Compensated Systems"

Massachusetts Institute of Technology June 29, 2010 Abstract—In a conference paper titled “Geometric Properties of Gradient Projection Anti-windup Compensated Systems,” two main results were presented. The first is the controller state- output consistency property of gradient projection anti-windup (GPAW) compensated controllers. The second is a geometric bounding condition relating the vector fields of the uncompen- sated and GPAW compensated closed-loop systems with respect to a star domain. While the controller state-output consistency property stands without modifications, the proof of the geometric bounding condition depends on two lemmas, the proofs of which were found to be faulty. In this report, we present a new proof of the geometric bounding condition using concepts from convex analysis, together with minor miscellaneous corrections.
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FALCON: a concept to extend adaptive optics corrections to cosmological fields

FALCON: a concept to extend adaptive optics corrections to cosmological fields

The approach we propose on FALCON differs totally from classical AO or MCAO. Instead of correcting the 25 arcmin Nasmyth FOV of the VLT as a whole, we only correct the regions of interest, i.e. the corresponding IFU superimposed to the observed galaxies 24 . To do this, we use several independent AO systems (one system per IFU). First, as the IFU size (~2x3 arcsec 2 ) is smaller than the isoplanatic patch, a single DM conjugated to the pupil can be used to correct the wavefront. In fact, we plan to use an “hybrid” corrector componed of a adaptive lens (for tip-tilt and defocus modes correction) and a micro-DM (for higher order modes), as DM are usually unable to correct low order modes (see section 5). Both the lens and the micro-DM will be placed in pupil planes and thus no MCAO-type corrections will be performed. Second, we assume that such a corrector and its pupil relay optics can be miniaturized to be integrated into the spectroscopic IFU, i.e. the so-called adaptive button. We think this technological challenge should be achievable within a few years thanks to the development of micro-DM. Third, we assume that the wave front sensor (WFS) can be miniaturized too and fit into a so-called WFS-button, which is similar to a spectroscopic IFU, but which is located on a guide star (no spectroscopy is performed here, just wavefront sensing). Therefore, all these new components (adaptive buttons and WFS-buttons) can be handled by an IFU-positioner (which might be OzPoz at VLT). However, this architecture departs from any other usual closed-loop AO system, as there is no optical feedback from the micro-DM to WFS. One solution is to integrate a micro-DM in each WFS-button and apply to it a command identical to that of the adaptive button. This "pseudo closed loop" is based on the assumption that all the micro-DM have the same behavior, which can be a critical point and requires accurate calibration: the loop is closed by “electro-mechanical analogy”. The FALCON AO loop represents therefore a difficulty and requires further studies on which we are currently working on.
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Rage, Criminal Justice, and Corrections

Rage, Criminal Justice, and Corrections

“He’s passin’ out shitpaper – headed this way. I’m  xin’ to gig the shit outta this fuckin’ toad”, he said, glee ringing in his voice. When the Building Tender – called a “BT” – had feigned ignorance to the whereabouts of the AB’s contraband, Hitman had secretly unscrewed the mophead, straightened the three-sixteenths diameter retainer loop into a two-foot-long spear, sharpened the tip and lashed it to the mopstick. It was now an oversized frog-gig. The shitter brush he’d soaked in wet towels over the weekend – after tearing all the bristles out. That was the sledgehammer which had bowled me out of bed all the way through the four inch-thick concrete wall between us. It had an eighteen inch-long oak handle as thick as a closet pole and was now a war hammer worthy of Thor.
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A two-band approach to nλ phase error corrections with LBTI's PHASECam

A two-band approach to nλ phase error corrections with LBTI's PHASECam

However, these issues with mis-declarations of fringe jumps may also be indicative of a different issue. In our implementation of the diffmod metric, by calculating both nominal raw phase values from the K band setpoint, we have implicitly assumed that the H band setpoint is the setpoint calculated from the ideal (4/3) proportion between the H and K phases. In practice, this is not the case. The H and K band setpoints have a differential offset, the predominant cause of which is the placement of the software apertures over which phase sensing calculations are done. Dispersion in the optical components of PHASECam and dispersion from water vapor also contribute. There is a calculation of this offset value in the PHASECam software, but its implementation with regards to fringe jump capture is still being revised. Implementing this, alongside finalizing the H band phase unwrapping algorithm as previously mentioned should significantly increase the accuracy of the diffmod loop. Correct determination of the H band setpoint will also allow us to make the transition from using the raw H and K band phases to the pinned phases. As previously described, this will center the measured phase values so that the maximum measurable error is not reduced by the choice of setpoint, increasing the Gaussianity of the noise statistics which should further increase the accuracy of the diffmod.
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Cosmological perturbation theory using the FFTLog: formalism and connection to QFT loop integrals

Cosmological perturbation theory using the FFTLog: formalism and connection to QFT loop integrals

One interesting aspect of the method described in this paper is that it relies on evaluation of loop integrals that are formally identical to those of a massless QFT. This is a new bridge between cosmology and particle physics and the full potential of this connection is still to be explored. This remains the major direction for future work. One hope is that many developments in the theory of scattering amplitudes will prove useful for going beyond the lowest order statistics discussed in this paper. The first step in this direction is a practical analytic formula for the one-loop trispectrum. In principle, that would allow the calculation of the three-loop power spectrum or the two-loop bispectrum. In practice, following procedure described in this paper may turn out to be too difficult or impractical. After all, the trispectrum is a function of six variables, which makes it much more complicated than examples we considered so far.
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Human-in-the-Loop Feature Selection

Human-in-the-Loop Feature Selection

Per-example feature selection has also been studied in (Avdiyenko, Bertschinger, and Jost 2012). They proposed a filter method based on the mutual information between fea- tures and target variables, conditioned on the specific val- ues of each example. The mutual information is then used as a score to rank the k most relevant features for each in- put. Their work contrasts with ours in two significant ways: (i) their method is deterministic and completely data-driven, whereas ours include human feedback to provide insights that cannot be automatically inferred from small or com- plex datasets; (ii) they build a subset sequentially, while our method produces a candidate subset in a single step, with no need for an arbitrary stop criterion.
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Periodic Corrections in Secular Milankovitch Theory Applied to Passive Debris Removal

Periodic Corrections in Secular Milankovitch Theory Applied to Passive Debris Removal

where rrr and vvv are the position and velocity vectors; ˆ θ θ θ = e H H H · ˆrrr/H. In this work, using the direct approach of Kozai [1], we will derive the short-period correction terms in the vectorial formulation for the J 2 effect only (contributions due to other perturbing forces will be addressed in future research) and apply these to determine the appropriate initial conditions in the osculating sense for targeting disposal regions depicted in mean element space in stability maps.

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Transcient behavior of biological loop models with application to the droop model

Transcient behavior of biological loop models with application to the droop model

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignemen[r]

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Tropospheric corrections of SAR interferograms with strong topography. Application to Etna

Tropospheric corrections of SAR interferograms with strong topography. Application to Etna

(1995) inter- preted the fringes observed on 1992-93 interferograms of Etna (without tropospheric correction) as the sum of a regional volcano-wide ground subsidence due to the [r]

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Multidimensional corrections to cell-centered finite volume methods for Maxwell equations

Multidimensional corrections to cell-centered finite volume methods for Maxwell equations

These results are of course a first step towards a study which would include charge and current densities, and more complex media. Future de- velopments for this study first include the generalization to heterogeneous media in order to treat aircraft coatings for example. In this context each component of the field is not a solution to a wave equation with uniform light velocity, therefore an extension of our method has to be derived. A careful study of which material constants ε and µ have to be considered has to be performed as in the case of the finite volume schemes [21].
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A Reinforcement Learning Approach to Protein Loop Modeling

A Reinforcement Learning Approach to Protein Loop Modeling

Proteins can be represented using simplified models where the degrees of freedom (DOFs) are the dihedral bond angles. The resulting search space is still vast even for relatively small loops. The protein loop modeling problem resembles the inverse kinematics (IK) problem in robotics and computer graphics where the protein’s backbone can be viewed as an articulated linkage. The goal then becomes to assign values to each of the dihedral angles such that the two ends of the loop keep connected to the rest of the protein, in effect closing the loop, while avoiding collisions with itself and the protein. Several robotics-inspired approaches to loop modeling have been proposed over the years [1], [2], [3]. Shehu and Kavraki provide a good review of the techniques applied to loop sampling [4].
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Hybrid constitutive modeling: data-driven learning of corrections to plasticity models

Hybrid constitutive modeling: data-driven learning of corrections to plasticity models

In recent times a lot of attention has been paid to the development of machine learning techniques able to unveil governing equations from data. This is specially important for constitutive equations that, unlike other more epistemologically sound equations—like equilibrium, for instance—are often phenomenological and inexact. Their precise expression is found by data fitting, leading very often to poor fitting to the experimental results.

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The indirect global warming potential and global temperature change potential due to methane oxidation

The indirect global warming potential and global temperature change potential due to methane oxidation

stratospheric water vapour, it does not take into account the production of carbon dioxide from methane oxidation. We argue here that this CO 2 -induced effect should be included for fossil sources of methane, which results in slightly larger GWP values for all time horizons. If the global temperature change potential is used as an alternative climate metric, then the impact of the CO 2 -induced effect is proportionally much larger. We also discuss what the correction term

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Density matrix approach to the complex heavy ion potential

Density matrix approach to the complex heavy ion potential

Then the potential energy density (2. 16) At this point we stress that the potential energy density (2. 16) depends on the intrinsic kinetic ener- gy density r' ' defined in Eq. 15) inst[r]

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Replicate This! Into the FESTAC Loop

Replicate This! Into the FESTAC Loop

ivory mask earlier this year. He regrets that political circumstances at present make it impossible for him to present the mask to the Nigerians, but he hopes that on a future occasion he will be able to do so. 120 As these lines suggest, it had belatedly dawned on the British government that its Nigerian counterpart might not, to put it mildly, find solace in a copy. Of particular interest here is the fact that both of the letters to Giles, as well as the memorandum quoted earlier relaying Eyo’s appalled response, postdate FESTAC: the first was written on July 29, 1977, and the second on October 11. Well after the festival had come to an end, the pendant bomb was still ticking. The replica was not ready in time for FESTAC. Museum records show it was crafted by Giles between June 3 and 15, a full five months after the event. Why this was remains unclear. What is certain is that in at least two instances after the festival, the FCO attempted to present the copy to representatives of the Nigerian government to no avail: they were not interested in even discussing the subject. One instance verges on the comical. In June 1977, the Commonwealth Meeting was hosted in London, bringing together twenty-six heads of government from across the anglophone world. In this context, Owen raised the matter of the replica with Joseph Nanven Garba, the Nigerian Commissioner for Foreign Affairs, and was met with stony silence. A related suggestion that the FCO seek out for Nigeria an alternative pendant rumored to be in private British hands was met with equal silence, or, as one memorandum put it, “studious avoidance.” 121 In the face of Nigeria’s steadfast refusal to engage, the FCO finally
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