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Questions tagged [supergravity]

Supergravity is a classical supersymmetric unification theory. It appears in low-energy classical limits of string-theory.

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358 views

Is there any way to distinguish experimentally gauge mediation from gravity mediation in an unambiguous way?

There are lots of models of gravity mediated SUSY breaking with various spectra as well as various general gauge mediation models. Are there any "smoking gun" experimental singnatures that could ...
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284 views

Why is full M-theory needed for compactification on singular 7-folds and what does that even mean?

In "M-theory on manifolds of $G_2$ holonomy: the first twenty years" by Duff, it is claimed (e.g. in section 8) that for compactification on singular 7-folds to be possible, we need to consider not ...
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191 views

How does one actually apply the M-theory/heterotic duality “fiberwise”?

It seems to be generally accepted ([1], [2]) that one can apply the duality between a $T^3$ compactification of heterotic string theory and a $\mathrm{K3}$ compactification of M-theory "fiberwise" to ...
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270 views

What is the global symmetry group associated to the C-field?

The C-field in 11-dimensional supergravity is an elusive object that is not the simple higher $\mathrm{U}(1)$-gauge field one would naively make this out to be. For an overview of possible models for ...
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92 views

Hybrid Inflation and Supergravity

Is it necessary to add a constant term in the superpotential of hybrid inflation within supergravity in order to cancel SUSY vacuum energy at the end of inflation?
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169 views

Moduli Stabilization in 6D Einstein-Maxwell theory - Fluxes and O3 planes

I'd like to do the maths for the moduli stabilization of 6D Einstein-Maxwell Gravity $$ S= \int d^6X \sqrt{-G_6}(M_6^4R_6[G_6]-M_6^2|F_2|^2), $$ where the 6D metric is specified by $$ ds^2 = g_{\mu\...
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Bosonic-Fermionic interactions in supersymmetry

There are a lot of supersymmetric theories, and, sometimes,in the Lagrangian, there are interacting terms between bosonic and fermionic degrees of freedom, and sometimes not. Why ? For instance, for ...
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Are there any SUSY black holes in D > 5?

Quoting from arXiv:0801.3471 Asymptotically flat BPS black hole solutions are known only for $d = 4,\,5$. and I've seen this claim very timidly suggested in a couple of other places, but I couldn'...
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Flux compactifications and the scalar potential

Does the scalar potential: $$V=e^K(K^{I \bar{J}})D_IW D_{\bar{J}}\bar{W}-3|W|^2$$ where $K$ is the Kähler potential and $W$ the superpotential, $D=\partial_I+\partial_IK$ and $I$ runs over all the ...
4
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114 views

Brane interactions?

In particle physics, in QFT's, interactions come from the interaction piece in the Lagrangian (action). In string theory, waiting for a complete formulation of SFT, we have to add "by hand" ...
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70 views

Constraint equation for Einstein-Hilbert action in Light-cone gauge

In Light cone coordinate system $(+,-,i)$, where $i=1,2$, the light cone coordinates are defined as $x^{\pm}=\frac{x^0 \pm x^3}{\sqrt{2}}$, if we consider the $+$ coordinate to be our "timelike" ...
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78 views

Fuzzy sphere of polarized D0 branes, non-abelian worldvolume action regime validity

I am studying Myer's paper "Dielectric Branes" (https://arxiv.org/abs/hep-th/9910053v2), where it is shown that a stack of D0 branes polarizes into a spherical D0-D2 bound state. The stack of $N$ D0 ...
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Starobinsky inflation in Supergravity

The available experimental data prefers plateau models of cosmic inflation, and among them Starobinsky inflation (aka R^2 inflation) is preferred, even if maybe not significantly. See here for summary ...
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D4 branes ending on NS5 branes (Witten's construction): query about harmonic functions

This query stems from Witten's paper, ''Solutions of Four-Dimensional Field Theories via M Theory'' (hep-th/9703166). Specifically, consider Type IIA string theory, and suppose one has a stack of NS5 ...
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147 views

Construction of the supergravity side explicitly in gauge/gravity dualities

Although the motivation of this question comes from the AdS/CFT correspondence, it actually is related to a more general principle of gauge/gravity duality. We know from Maldacena's conjecture that a $...
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29 views

What is the high-energy/superstring analogue of wave function?

Chapter 12 of Beckers' book about superstrings and m-theory lists several deep dualities between low energy gauge theories and high energy superstring theories. I am only at the Chapter 2, that is why ...
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87 views

D-brane worldvolume actions: Where are the Fermions?

I am studying D$p$-brane polarization (Myer's effect https://arxiv.org/abs/hep-th/9910053) and brane-flux annihilation (KPV mechanism, https://arxiv.org/abs/hep-th/0112197). There is little to no ...
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39 views

Anomalous curvature coupling corrections for $Dp$-branes worldvolume actions

The Chern-Simons term of an (abelian brane) is commonly written as $$ \sim\int_{\mathcal M_{p+1}}\sum_iC_{i}[e^{2\pi\alpha'F+B}], $$ where $C_i$ is the background Ramond-Ramond $i$-form, $F$ is the ...
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105 views

Why a Christoffel connection is inconsistent with local supersymmetry?

I'm doing an introductory studying on supergravity, and I'm studying in particular on the book Supergravity of D. Z. Freedman and A.V. Proeyen. In this book they describe supersymmetry using Majorana ...
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120 views

Dimensional reduction from even to odd dimensions and Chern-Simons terms

I'll be taking some Lagrangians from this paper to try and keep personal typos out of the discussion I have been looking at the dimensional reduction of Einstein-Maxwell-Dilaton theories and I am ...
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165 views

Corrections to precession of the perihelion of Mercury

Consider one of the classical observables of General Relativity, the precession of the perihelion of an elliptical orbit: $$ \delta\varphi=\frac{6\pi G^2M^2m^2}{c^2L^2} $$ I am interested in known ...
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484 views

Variation of the Spin Connection

I am trying to get an explicit expression for the variation $\delta \omega_{\mu}^{\ ab} / \delta e_\mu^a$, but when doing the actual variation I end up with a series of 16 terms that I cannot simplify ...
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78 views

Twisted Bianchi identity for D6-branes from M-theory?

The descent of the M2/M5-brane charges to the Dp-brane charges and their twisted Bianchi identites $\mathrm{d} F_{p+2} = H_3 \wedge F_p$ is straightforward for $p = 0,2,4$. (This is spelled out ...
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168 views

Question on $E_8$ and twistor space

The Kahler $4$ form constructed from two-forms $\{\alpha, \beta\} \in H^2(M,\mathbb Z)$, and $M$ a $4$-manifold, is induced by $\alpha\wedge\beta$ with the map $H^2(M, \mathbb Z)\otimes H^2(M, \mathbb ...
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71 views

What is the origin of the five-form field in bubbling Ads geometries?

I have been reading the paper: Bubbling Ads space and the 1/2 BPS geometries[hep-th/0409174]. In the paper they look at 1/2 BPS states in the field theory which are dual to D3 branes IIB supegravity. ...
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79 views

Supersymmetry breaking and normalizable zero modes

Why does supersymmetry always lead to normalizable zero modes? For example, it is stated in the paper by Michelson and Kaplan (http://arxiv.org/abs/hep-th/9510053) that we can assume, without loss of ...
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97 views

What is the Origin and physical meaning of R- multiplet and S-multiplet in Sugra?

In this summer, i learnt about various muliplet in Supergravity. First i summarize what i learn from the school. (i) Ferrar-Zumino multiplet The super-current multiplet satisfies \begin{align} \...
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91 views

supersymmetry in 2,6,10 dimension

Why the susy has chirality in above (2,6,10) dimension? What i am saying is that for $2, 6, 10$ dimension we can write as follows For 2d : $N=(16,16), \cdots N=(2,2), N=(2,0), N=(1,1), N=(1,0)$ are ...
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49 views

Stability condition for AdS background (when gravity coupled to matter fields)

In finding the stability condition for AdS background (when gravity coupled to matter fields), why the conserved energy should be positive?
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135 views

Does the covariant derivative of a derivative of the metric vanish?

The title holds the main question. For a little more backgroud: In a calculation I keep coming across terms of the form $$ D_M \partial_N e_P^A \overset{?}{=} 0$$ where $e_P^A$ is the vielbein and $...
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26 views

What is a global limit in gauged supergravity?

Does anyone know what a global limit (rigid limit), where the gauge coupling constant is zero, in gauged supergravity is?
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49 views

What is the relation between a $D_2$-brane and an $M2$-brane?

I am only familiar with the concept of a $D_2$-brane from a first course in String theory. I would like to learn, at least on a conceptual level, what an $M2$-brane is and what is its relation to the $...
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61 views

Why should fermions vanish for a solution of a supergravity theory that preserves supersymmetry?

On p.249 of Freedman and Van Proeyen's Supergravity, the following is stated: "Given the action of a supergravity theory, it is generally useful to search for solutions of the classical equations ...
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Would N=8 Supergravity solve quantum gravity if it was finite?

If N=8 Supergravity turned out to be finite to all loops in Feynman diagrams, would it be a complete theory of quantum gravity? Some people have said that a theory like loop quantum gravity is needed ...
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28 views

New-minimal vs old-minimal supergravity

New-minimal set of supergravity auxiliary fields includes a two-form field, whereas the old-minimal auxiliary set includes a vector and a complex scalar. Is anyone aware of how to transform between ...
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112 views

$D=10$ Type IIB Supergravity action

In this review of SUSY gauge theories and the $AdS-CFT$ correspondence, on Page-29, firstly the Supergravity action for $D = 11$ is written. The authors then say that the action for the Type IIA ...
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Maximum number of dimensions in string/M-theory

M-theory low energy limit is eleven-dimensional supergravity. However I understand that Itzhak Bars and others have been working in generalizations of string theories of 12, 13 and 14 dimensions with ...
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72 views

Why Can't $AdS_5$ SUSY Extremal Black Holes be Large?

When we put the BPS condition and the extremality condition together on the most general black hole solution in $AdS_5$ (with minimally gauged supergravity), we get that the relation between the ...
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109 views

Compactification on $S^n$ and supersymmetry

Does compactification of $(D+1)$-dimensional supergravities on $S^n$ as (1): $\mathbb{R}^{1,D-n}\times S^n$, and (2): $AdS_{D+1-n}\times S^n$ break all of supersymmetery? My understanding of the ...
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132 views

Form of scalar potential in SUSY/SUGRA $\sigma$-models

In supersymmetry or supergravity, textbooks always show that one can define a Kähler potential $K=K(\phi^i,(\phi^i)^\ast)$ and an holomorphic superpotential $W=W(\phi_i)$ such that the scalar ...
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211 views

Central charges in the supersymmetry algebra of the $d = 10$ Type-IIA theory

According to Witten's paper, ''String Theory Dynamics in Various Dimensions'' [arXiv:hep-th/9503124], the supersymmetry algebra for the Type-IIA theory in 10 dimensions has the structure $\{Q, Q\} \...
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76 views

How to find curved superspace vielbein and connection?

Need help with finding total curved superspace vielbein and connection in terms of SUGRA multiplet components (graviton, gravitino, auxiliary real vector and complex scalar). In Wess and Bagger ...
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124 views

Gauged supergravity

It is said that in N=2 supergravity coupled to vector multiplets and hypermultiplets, one can gauge the R-symmetry by equivalently gauging the isometries of the corresponding hyperkahler cone over the ...
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Is there any known dynamical process to obtain supertubes?

I'm looking for a dynamical process to produce supertubes. For example, microstates of the D1-D5 black hole system can be understood as supertubes. See, for example, http://arxiv.org/abs/hep-th/...
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88 views

How to visualize a sphere bundle?

In the paper ``Gravitational Anomaly Cancellation for M Theory Fivebranes", the authors consider removing a tubular region of radius $\epsilon$ around the M5 brane (in order to make sense of the three ...
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91 views

Instantons and Fivebranes

What is the general relationship between instantons and fivebranes? In the paper ``Magnetic Monopoles in String Theory'' by Gauntlett, Harvey and Liu, the authors state the fivebrane ansatz of ...
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0answers
124 views

What is the significance of self-duality and anti self-duality in supergravity?

So I see the terms "self-dual" and "anti self-dual" appear routinely in supergravity/string thery, e.g. the fact that Type IIB supergravity contains a real self-dual rank-5 antisymmetric tensor $F_{\...
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0answers
72 views

Supergravity solution, metric for the total space, and connection

In supergravity solutions, one sometimes encounters the case where the manifold may be a bundle over some base space, and one has to write down the explicit metric regarding such bundle. I would like ...
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107 views

Does anyone know how to symmetrize $\gamma$-matrices?

I'm trying to construct the SO(5, 5) $\gamma$-matrices which are real and symmetric. Recently, I have 6 symmetric and 4 antisymmetric $\gamma$-matrices ($6_S + 4_A$ representation). How can I ...
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0answers
26 views

Sources to learn about Killing spinors

What are some good sources to learn about Killing spinors from? I am currently learning about Killing vectors and how they are the generators of a Lie algebra that corresponds to the isometry group ...