Questions tagged [supergravity]
Supergravity is a classical supersymmetric unification theory that appears in low-energy classical limits of string theory.
101 questions with no upvoted or accepted answers
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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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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&...
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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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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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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
$$
ds^2 = g_{\mu\...
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Is the $\alpha'$ expansion in string theory an asymptotic expansion?
The low-energy bosonic effective actions of string theory lead to Einstein-Hilbert gravity, along with scalars and $p$-form Maxwell fields. For example, the action for type IIA string theory is
$S = \...
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Are there any SUSY black holes in D > 5?
Quoting from arXiv:0801.3471
Asymptotically flat BPS black hole solutions are known only for $d = 4,\,5$.
and I've seen this claim very timidly suggested in a couple of other places, but I couldn'...
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Problems with covariant action of the superstring
I was reading Kiritsis' notes (http://arxiv.org/abs/hep-th/9709062), at page 105/106 (equation 10.1), where he has a covariant action of the superstring including the gravitino. I have problems ...
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Bosonic-Fermionic interactions in supersymmetry
There are a lot of supersymmetric theories, and, sometimes,in the Lagrangian, there are interacting terms between bosonic and fermionic degrees of freedom, and sometimes not. Why ?
For instance, for ...
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Spin-2 operators from metric fluctuations in the AdS/CFT
This is a computational question. I am pretty sure that there is a simple explanation, and something obvious that I am missing but I cannot figure it out.
I want to add that this is not meant to be a &...
user172341
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Flux compactifications and the scalar potential
Does the scalar potential:
$$V=e^K(K^{I \bar{J}})D_IW D_{\bar{J}}\bar{W}-3|W|^2$$
where $K$ is the Kähler potential and $W$ the superpotential, $D=\partial_I+\partial_IK$ and $I$ runs over all the ...
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Coupling spin 3/2 fields with electromagnetism (causally)
I am trying to read literature regarding the coupling of massive spin-$\frac{3}{2}$ fields with electromagnetism. Apparently, an elementary (i.e. not composite) massive spin-$\frac{3}{2}$ field can't ...
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Tadpole cancellation condition for $C_4$ in Type IIB Supergravity theory
In the following I use Polchinski's notation.
Type IIB Supergravity action (with non-vanishing fluxes & $\rm{D3}$-branes) contains
\begin{align}
S_{\mathrm{IIB}} &= S_{\mathrm{NS}} + S_{\...
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D4 branes ending on NS5 branes (Witten's construction): query about harmonic functions
This query stems from Witten's paper, ''Solutions of Four-Dimensional Field Theories via M Theory'' (hep-th/9703166). Specifically, consider Type IIA string theory, and suppose one has a stack of NS5 ...
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Brane interactions?
In particle physics, in QFT's, interactions come from the interaction piece in the Lagrangian (action). In string theory, waiting for a complete formulation of SFT, we have to add "by hand" ...
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Is a non-trivial Kaehler Manifold in Supergravity compatible with the Standard model?
Actually, I already asked a similar question Coupling of supergravity to matter which has remained unanswered. So this time I will be less general.
In the very interesting paper arXiv:2212.10044 [...
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Anti-de Sitter superalgebra from preserved symmetry
Following Freedman & Van Proeyen's "Supergravity", the $\mathcal{N}=1,\, D=4$ AdS supergravity action is
$$ \dfrac{1}{2\kappa^2}\int d^4x \; e \left[R(\omega) - \bar{\psi}_\mu \gamma^{\...
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What is NS5 brane?
NS5 brane can be considered as 1/2 BPS solution
in supergravity (with other solutions to compare):
This branes of Type IIA/B supergravity are expected to extend to solutions of the full Type IIA/B ...
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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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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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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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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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$D=10$ 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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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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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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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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Is a spin connection with torsion possible whereas the affine connection is only Levi-Civita (torsion-free) in Supergravity?
In the paper "Simple Supergravity" from G. Dall'Agata & M. Zagermann (arXiv:2212.10044v2 15 Feb. 2023) on page 8 when it comes to the antisymmetric part of the covariant derivative of ...
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How do I obtain the low energy supergravity actions from the 5 superstring theories?
In Domain-Walls and Gauged Supergravities by T.C. de Witt, there is a small table giving the 5 string theories and each of their effective sugras. I am looking for detailed reviews of how these sugras ...
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Why do spherical M2 branes have no net charge?
In the paper Invasion of the Giant Gravitons from Anti de Sitter Space, the authors claim that
We are interested in the dynamics of a relativistic spherical membrane moving in $S^4$. The
membrane has ...
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Why do the scalars always occupy the coset they do?
If I reduce a $D$-dimensional theory on a $d$-dimensional manifold $M_d$, then I will be left with some reduced, effectively $(D-d)$-dimensional theory with some global symmetry group $G$. In general, ...
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How to construct the final action for a supergravity theory $N = 1$ in 4D?
I am trying to understand the basics of supergravity theory $N = 1$ in 4D, which combines supersymmetry and general relativity. I know that the theory involves a spin 2 field whose quantum is the ...
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Dimensional reduction of supermultiplets
Consider the (10d) IIA supergravity multiplet: (in terms of $SO(8)$ representations) a graviton $\boldsymbol{44}$, a 1-form $\boldsymbol{8}_V$, a 2-form $\boldsymbol{28}$, a 3-form $\boldsymbol{56}_V$,...
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Supergravity in our universe of accelerated expansion
In "On supergravity theories, after ~40 years" (Jean-Pierre Derendinger) presented on DISCRETE 2014" it is said (p.16) that a positive cosmological constant is not compatible with ...
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Can local supersymmetry be characterized entirely in terms of observables?
Global symmetries can be defined through their effect on observables. In contrast, quantum theories are often constructed with the help of symmetries that leave observables invariant, like the ...
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Why does the perturbative ($\mathcal{N}$=8, d=4) supergravity and type IIB closed string compactified on $T^{6}$ spectrums coincide?
The observation is that the perturbative spectrum of $\mathcal{N}$=8 supergravity in four dimensions is exactly the same as the type IIB closed superstring spectrum after dimensional reduction on $T^{...
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Why does invariance commute with partial derivative?
This question applies more generally to actions, but I am going to ask it for a specific example.
I am getting confused when considering the invariance of the superstring action under Weyl ...
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Holographic duals of (super)gravity sigma models
Consider a (super)gravity theory on asymptotically AdS spacetime $N$ with fixed conformal boundary $\partial N$ coupled to scalars $\phi_i$ taking values in a manifold $M$, possibly in addition to ...
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Toroidal compactifications of type IIB string Theory and $SO(5,5)/(SO(5)\times SO(5))$ invariant 6D sugra action
It is usually stated that the compactification of (the bosonic part of the) type IIB ($D=10$, ${\cal N}=(2,0)$) supergravity on $\mathbb{T}^4$ gives a six-dimensional ${\cal N}=(4,4)$ supergravity ...
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Supergravity and Gamma Matrices
On page 101 of Freedman and Van Proeyen's book on Supergravity they find the propagator of the gravitino, however I'm not sure how to work through the steps in (5.30), and hints or answers would be ...
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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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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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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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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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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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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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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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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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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 ...
- 12.9k
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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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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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