A postulated symmetry between bosonic and fermionic fields in quantum field theories and string theories.

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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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72 views

“Constant Fermion”

I was talking to a professor in my institution which works in Lorentz Violation of various QF theories. While we talk about a SUSY lagrangian, I asked him if we could have a fermion acquiring VEV and ...
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68 views

Why is Seiberg duality called an electromagnetic duality?

An electromagnetic duality is a duality that maps electric to magnetic degrees of freedom of two distinct theories. Apart from source-less Maxwell electrodynamics, other theories require magnetic ...
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16 views

How relevant are non-minimal Kahler potentials in supergravities?

Does it make sense to consider non-minimal Kahler potential of the form $K\sim|\phi|^4$? Or, to slightly rephrase the question, can we altogether ignore scalar kinetic terms with coefficients ...
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123 views

What does the discovery of the Higgs boson mean for SUSY?

I've seen many differing opinions on how the discovery of the Higgs boson (specifically due to its mass) has effected theories of Super Symmetry, but all seem fairly biased. I'm wondering if someone ...
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52 views

D-branes conserving only half of the supersymmetries

Concerning D-branes as BPS states from T-duality. In D-Branes by Johnson (and other sources) I find the following statement (p.196): "Only the total [supersymmetric] charge of $Q_a+\tilde{Q}_a$ of ...
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35 views

What is a “Scalar Manifold”?

I'm trying to understand a recent paper working within the context of $\mathcal{N}=8$ gauged supergravity with gauge group $\rm{SO}(6)$. There are a number of statements along the lines of: "...the ...
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188 views

Intuition for S-duality

first of all, I need to confess my ignorance with respect to any physics since I'm a mathematician. I'm interested in the physical intuition of the Langlands program, therefore I need to understand ...
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41 views

Confusion about supergravity multiplet

I have a bit of confusion with the following consideration. Generally, to impose some BPS condition (i.e. to check if some multiplet preserves some SUSY charges) one imposes to zero the SUSY ...
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35 views

Supersymmetry algebra convention?

As derived for instance in this review (page 23-24), the supersymmetry algebra involving grassmann valued generators $Q_\alpha$ and ${\bar Q}_{\dot\alpha}$ is given by: ...
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44 views

Supersymmetrizing bosonic actions at higher orders

Given only the bosonic terms of a supersymmetric action, using a knowledge of the (local) supersymmetry transformations, is there a systematic way of reconstructing the fermionic terms? More ...
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69 views

Supersymmetry and grand unification

I came across this diagram in my introductory particle physics class. Given the fact that SUSY can make the plot look suspiciously nice, what can we do with it? Also, electromagnetism has been ...
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Equivariance Relation - Superconformal Hypermultiplets

I'm concerned with equation 2.24 of http://arxiv.org/abs/1601.00482 The superconformal hypermultiplets in this paper have a conic hyperkahler target manifold and the authors want to gauge some ...
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122 views

What is the motivation for using Calabi-Yau manifolds in string theory?

I have just begin to study Calabi-Yau compactification. Looking in many book I found that, if we start with a critical superstring theory in $D=10$, we are in search of a compact $D=6$ Calabi-Yau ...
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339 views

What's the Coulomb Branch and why is it important?

I'm studying the introduction of flavour degrees of freedom in the AdS/CFT correspondence and now I'm supposed to calculate the mass spectrum of mesons in the Coulomb branch. I have searched the ...
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1answer
188 views

Showing closure of the SUSY algebra of a free abelian gauge multiplet

Given the complete supersymmetric lagrangian of a free abelian gauge multiplet $$ \mathcal{L} = -\frac{1}{4} F_{\mu\nu} F^{\mu\nu} + i \bar{\lambda} \bar{\sigma}^\mu \partial_\mu \lambda + \frac{1}{2} ...
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64 views

Supersymmetric background and fermion variations

I'm trying to understand some basic questions about supersymmetric theories in curved backgrounds and supergravity. If I understand it correctly, there's a condition for a background to preserve SUSY, ...
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24 views

Which supersymmetry principles make the axio-dilaton field in F-theory holomorphic?

I am following the lecture notes on F-theory by T. Weigand . On page 7 he states that when considering F-theory as the strong coupling limit of type IIB orientifolds with D-branes, the axio-dilaton ...
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345 views

Apparent failure of SUSY nonrenormalization theorem

I am having trouble reconciling two pieces of information. Consider supersymmetric QED, i.e. a supersymmetric U(1) gauge theory with two chiral superfields of opposite charges, $h$ and $\hat{h}$. The ...
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71 views

What is the Lorentz group representation for a general spin?

Setup, as I understand things so far: One way to think about where the spin of a quantum field comes from is that it is a consequence of the ways that different types of fields transform under ...
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43 views

Why supersymmetry requires either left or right movers to vanish for a $S^1$ compactification

In the chapter on Black holes in string theory (Section 11.4, page 584 near equation 11.94) in the book by Becker, Becker and Schwarz, they write [...] let us consider a single string wound $Q_1 ...
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53 views

SUSY Multiplets

Why is it that in vector supermultiplets, the left and right chiral components of the gauginos must transform in the same representations of all gauge groups, i.e a chiral theory for such fermions is ...
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50 views

Boson in Superstring

I'm confused about a point. Superstring sigma model is $$ S=-\frac{T}{2}\int\mathrm{d}^2z \left[\eta^{ab}\partial_aX^\mu\partial_b X_\mu -i\bar\psi^\mu\rho^a\partial_a\psi_\mu \right], $$ of course, ...
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On the action of superconformal generators in maximally supersymmetric Yang-Mills

Consider maximally supersymmetric Yang-Mills theory in 3+1 dimensions. This theory has 32 supercharges: 16 ordinary ones, conventionally labeled $Q$; and 16 superconformal ones, conventionally ...
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26 views

Gauge mediated SUSY breaking

I have seen it claimed that in SUSY gauge mediated breaking there can be no flavour changing terms because the mediation is flavour blind. What does this mean and how does it work?
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66 views

How does SUSY avoid to create non-Lorentz interactions?

A three-legs fermion interaction or boson absorbing a fermion are things we do not see in QFT because the corresponding terms in the Lagrangian are not Lorentz invariant. But in susy, naively, such ...
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Has anyone studied anomalous supersymmetry?

In this paper (and others), the authors study a supersymmetric model where the supercharge suffers an ABJ anomaly. Has anyone studied a supersymmetry with a 't Hooft anomaly (gauging the ...
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725 views

How exactly do superstrings reduce the number of dimensions in bosonic string theory from 26 to 10 and remove the tachyons?

In bosonic string theory, to obtain the photon as the first excited state, the ground state must have a negative mass (tachyon). By applying $1 + 2 + 3 + \cdots = -1/12$, it can be shown (in a ...
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148 views

Reflectionless potentials in quantum mechanics

Scattering on potential $$V(x) = -\frac{(\hbar a)^2}{m}\text{sech}^2(ax)$$ with 1D equation of Schrodinger is famous problem. It is dealt with in Problem 2.48 of Griffiths book or online here. It is ...
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32 views

$\mathcal{N} = 4$ Super-Yang Mills propagators

In $\mathcal{N} = 4$ Super-Yang mills there are only massless particles. If one wishes to obtain a heavy quark one can see the SYM theory as a stack of (N+1)-branes in AdS$_5 \times$S$^5$ where one ...
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37 views

Number of supercharges in $N\ge 1$ SUSY in $d\ge4$ dimensions

I have a couple of questions concerning supercharges and superalgebras: 1, In four-dimensions, the minimal spinor representations are Weyl spinors. These have 4 real degrees of freedom (dof). This ...
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19 views

Fermion Trucation

I recently posted about truncating fermions in supergravity Lagrangians and got a good answer about how this gives a vev to the bosonic content and therefore freezes it to a stationary point of the ...
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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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68 views

Ignoring fermions in string theory/supergravity

Often in string theory/supergravity, papers will say something along the lines of "we set all the fermions to zero and focus purely on the bosonic field content". See e.g. the final lines on p3 of ...
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202 views

Mass of a superstring between two branes?

A open bosonic string between two parallel branes seems to obey formulae such as $M^2 = \big((n + {\theta_i - \theta_j \over 2 \pi}) {R' \over \alpha'}\big)^2 + {N-1 \over \alpha'} $ So that the ...
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What is the Superpartner of a glass? [closed]

A little context: This summer I visited Switzerland and had the chance to tour CERN. While there, I saw through an open door this question written at the top of a chalkboard in someone's office. I ...
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1answer
52 views

Nonperturbative corrections that can break SUSY

I am puzzled by a statement that is made regarding non-perturbative corrections breaking supersymmetry. Specifically, consider a one-dimensional system, described by the Hamiltonian $$H = ...
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1answer
35 views

What is the role of chiral compensator?

When studying SUGRA inflation, I stumbled upon a notion of "chiral compensator". What is its role? I don't remember seeing it in Wess & Bagger textbook.
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Why are symmetrical structures highly stable?

What makes symmetrical structures(geometry) highly stable? It is perfect to say that the forces acting on a symmetrical structure is balanced and hence stable. But why is it so? To be more specific, ...
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28 views

Why must SUSY be broken in SUGRA inflation?

Why must supersymmetry be broken during the inflation in supergravity models? How does adding supersymmetry to power-law or Starobinsky models spoil inflation? And is breaking of SUSY needed for ...
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23 views

$R$-Symmetry Group

On p238/239 of the Freedman and van Proeyen book on Supergravity, they show how the $R$-symmetry group must be $U(\mathcal{N})$ for $\mathcal{N}$-extended supersymmetry in $d=4$. At the bottom of ...
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22 views

Tranformation of a spinor in the self representation and conjugate representation of $SL(2,\mathbb{C})$

The transformation rules for a spinors as per Introduction to Supersymmetry by Wiedamann on Pg.38 is be summarized as: $$\begin{align} \psi_{\alpha} \mapsto \psi'_{\alpha} &= ...
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Question about the superconformal index

According to arXiv:1507.08553v1, the superconformal index, defined by $$I(\beta_j) = \mbox{Tr}_{\mathcal{H}}(-1)^F e^{-\gamma\{Q,Q^\dagger\}}e^{-\sum_{j}\beta_j t_j}$$ is independent of the ...
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What do different supercharges corrrespond to? Is creation mathematically close to fock space?

We may have $I =1,2,..N$ where it is said that this corresponds to $N$ supercharges, $Q^I$. By the supersymmetry algebra, $$[M_{\mu\nu},{\overline{Q}}^{I\dot{\alpha}}] = ...
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49 views

Coleman Mandula theorem and translations

I don't know what Coleman Mandula theorem is, however if I were forced to say something about it, I will say it is a statement that suggests that internal and spatial symmetries have no unique ...
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54 views

Physical meaning of the Morse functions? [closed]

What is the physical correspondence of the Morse functions in a physical system? Currently I am studying Mirror symmetry but I can not get a physical intuition out of it.
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How do I obtain the SUSY Transformations from Poisson Brackets?

In Friedman's and Van Proyen's Supergravity textbook it is explained how one can get the supersymmetry transformations using the conserved currents. Specifically this is in section 6 where we are ...
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Supertrace of holonomy of commutator

On page 47 of Surface operators in four-dimensional topological gauge theory and Langlands duality by Kapustin et al., the following expression is given \begin{equation} ...
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Femionic vacuum expectation value

To have maximally symmetric space-time (Minkowski, dS and AdS), why should we have zero vacuum expectation value for fermionic fields?
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38 views

Number of components of a One-Form Superfield

A Supersymmetric Yang Mills theory has 8 bosonic and 8 fermionic components. Since SUSY YM Theory is described via the Vector Superfield, $$V=C(x)+i\theta\chi(x)-i\bar{\theta}\bar{\chi}(x) \dots.$$ ...