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

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Representation theory and the Nekrasov partition function

Is there any review or lecture notes on the Nekrasov partition function which particularly thinks of this from a representation theorist's point of view? Some possibly related references I know of ...
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1answer
97 views

Dimensional reduction of SUSY theories

I know that if one reduces 10 dimensional $\mathcal{N}=1$ SYM theory to 4 dimensions one gets $\mathcal{N}=4$ SYM. There are other examples also. I have two related questions regarding this fact. ...
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101 views

Supersymmetric transformation of general Wess-Zumino Lagrangian

I suspect that I might have understood something wrong here. I'm trying to show that the general Wess-Zumino Lagrangian \begin{align} \mathcal{L} &= \int d^2\theta d^2\bar{\theta} K(\Phi^*, \Phi) +...
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53 views

Can i use the $y^*$ representation of the chiral covariant derivatives on a superfield that contains both $y$ and $y^*$?

Imagine I want to compute this $$D^{\dagger2}D_{\alpha}(\Phi^*\Phi)$$ where the $D$-s are super-covariant derivatives and $\Phi$ is a chiral superfield. Following the notation of this review on ...
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27 views

Which is the analogous of the unitarity constraint of chiral perturbation theory in superchiral perturbation theory?

I am trying to reconstruct something and I would appreciate omeone helping me filling the gaps. To motivate my question let's first consider chiral perturbation theory with up and down quarks. This is ...
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55 views
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269 views

Book with solved examples and exercise problems for SUSY

I am learning supersymmetry right now. I am mostly following Bailin and Love. I try to connect all the steps from the book and complete the derivations in order to get comfortable with the ...
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1answer
89 views

Why must superpartners have the same gauge quantum numbers?

The title leaves it quite clear, why must superpartners have the same gauge quantum numbers?
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67 views

What is $\mathcal{N}=2$ QED?

I would like to know is $\mathcal{N}=2$ QED is simply a $\mathcal{N}=2$ theory with gauge group $U(1)$ like in normal QED? If not, exactly what theory is it? Is there some reference for it?
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158 views

Should the (On-shell) (2+1)d $N=2$ Chiral Multiplet Contain Two Scalars and Two Majorana Spinors?

In supermultiplets, the bosonic degrees of freedom and the fermionic degrees of freedom need to match in number. The number of degrees of freedom of a field corresponds to the number of independent ...
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83 views

(Super)Gauge Fixing in Supersymmetry

I have three questions about gauge fixing in supersymmetry, one is general and the other two explicit: Why gauge fixing seems not important in supersymmetry? By "not important" I mean gauge fixing ...
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61 views

Projection that keeps graviton but gets rid of B-field

We consider the closed superstring and the massless states in the (NS,NS)-sector \begin{equation} \tilde{b}^i_{-\frac{1}{2}} |0\rangle_L \otimes b^j_{-\frac{1}{2}} |0\rangle_R. \end{equation} It is ...
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555 views

What is special about a 126 GeV Higgs mass?

The 126 GeV Higgs mass seems to be a rather special value, from all the a priori possible values. One thing I've heard is that it is just at the edge of the mass range implying a stable vacuum, and ...
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127 views

Quantum mechanic particle

In non relativistic quantum mechanic, we are dealing with a problem involving a particle in one dimensional space, and it has been given the potential and it reads: $$V(x)~=~A'(x)^2-\frac{\hbar}{\...
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1answer
192 views

Methods of detecting gravitino DM and possible implications for theories of everything

Let me summarize my thoughts about topics in theoretical physics: Theory of everything: The theory of everything aims to unite all the four forces of nature into one single elegant equation. ...
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393 views

Stablising the Higgs without SUSY

Should the Higgs be found at the LHC, but no supersymmetry (assuming for the sake of argument that the LHC be capable of eliminating all versions of SUSY that are motivated by solving the hierarchy ...
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1answer
449 views

What is the $\mu$ problem in SUSY?

I need a little bit of help in understanding the mu problem in SUSY. As I understand it, the gist of the problem is that $\mu$ must be on the same order of magnitude as the electroweak scale (246 GeV)....
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584 views

Hierarchy is no problem and susy is a mathematical tool for data fitting

I saw this paper in the arXiv: http://arxiv.org/abs/1206.4711. The author seems well-known and has many very well cited papers. But what he says sounds very strange. What I get from this paper are ...
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84 views

supersymmetry in 7, 8, 9 dimension

Why above dimension (7,8,9) the number of supercharge per supersymmetry is equal? $i.e$ For 32 supercharges, supersymmetry in 7,8,9 dimension is describe by $N=2$. And for 16 supercharges, ...
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58 views

Polchinski, (0,0) picture vertex operator

I am currently working through chapter 12 of Polchinski and am confused as to how the equation $(12.3.39)$ for the (0,0) picture vertex operator arises. From the text: The state–operator mapping ...
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275 views

Understanding Fierz rearrangement identity

I'm trying to get a better grasp of the Fierz rearrangement identity for 2-component spinors (Equation 2.20 I'll be using the Van der Waerden notionation used in the given link) $$ \chi_\alpha (\xi \...
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1answer
232 views

Signs of supersymmetry and thus dark matter at CERN

The Large Hadron Collider at CERN has just re-started after a two year pause and is now running at unprecedented levels of 6.5 TeV, with collisions that will release up to 13.5 TeV. With this increase ...
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103 views

What is meant by “the superpotential is not renormalized”?

Reading about supersymmetry I often read the phrase because of the non-renormalization theorems the superpotential is not renormalized. I would like someone to be more explicit on what is ...
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97 views

Do the Grassmann coordinates in the superfield formalism have any physical meaning?

In the superfield formalism we consider fields in a space who has four so called bosonic coordinates $x^{\nu}$ and four so called fermionic coordinates $\theta_1$,$\theta_2$,$\bar{\theta_1}$,$\bar{\...
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1answer
70 views

Partial derivatives of chiral superfields with respect to scalar components in the superpotential

I am following some notes on supersymmetry by Matteo Bertolini and I need some clarification. Chapter five deals with sypersymmetric Lagrangians and the superpotential is introduced. It is stated ...
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73 views

Supermultiplet dimensions from Young Tableaus

In John Terning's book, on pages 14 and 15, there are lists of $\mathcal{N} = 2$ and $\mathcal{N} = 4$ supermultiplets, labeled in terms of the dimensions of the corresponding R-symmetry $d_R$ and ...
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106 views

Why must the supersymmetry generators be spinors?

I have read in a few places (for example, at page 5 here) that the supersymmetry generators must be spinors. Quoting the reference mentioned The generator of the symmetry must relate two types of ...
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92 views

Elementary question about global supersymmetry of a worldsheet [closed]

I'm reading chapter 4 of the book by Green, Schwarz and Witten. They consider an action $$ S = -\frac{1}{2\pi} \int d^2 \sigma \left( \partial_\alpha X^\mu \partial^\alpha X_\mu - i \bar \psi^\mu \rho^...
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158 views

With the LHC about to restart as max energy, are there absolutely no hints or tantalizing signs of Supersymmetry in previous data?

Over the last couple of years I've seen several articles talk about hints or bumps in the data that might point to Supersymmetry. An article in NewScientist from Summer 2012 discussed the discovery of ...
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72 views

Why we do we consider explicit SUSY breaking in the MSSM and not an spontaneous breaking of SUSY?

Reading about the minimal supersymmetric standard model (MSSM) I have found that an explicit breaking of supersymmetry is considered, given by the term $$\cal{L}_{soft}$$ where soft supersymmetry ...
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90 views

What mathematical structure describes superspace and superfields?

In every book related to supersymmetry I have encountered at some point the idea of superspace is introduced. Superspace is presented as a space spanned by 4 "normal" directions and 4 Grassmannian ...
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69 views

How can we see that a 4D N = 2 sigma model will yield a 3D N = 4 sigma model when compactified on a circle?

I have a question about sigma models in 3D. If we have $\mathcal{N}=2$ field theory on $\mathbb{R}^4$ and compactify it on $\mathbb{R}^3 \times S^1_R$ (in which $S^1_R$ is a circle of radius $R$) we ...
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54 views

Supersymmetry invariants

On page 158 of Fields, the supersymmetry algebra is represented in terms of the action on supercoordinates as $$\delta \theta^\alpha = \epsilon^\alpha$$ $$\delta\bar{\theta}^{\dot{\alpha}} = \bar{\...
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111 views

Intro to Super Yang Mills theory

I'm looking to start learning Super Yang Mills theory. Currently I have studied Peskin and Schroeder up to the Renormalization Group, but don't know supersymmetry yet. I know some Conformal Field ...
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1answer
34 views

Why is the mass dimension of anticommutingcoordinates $[Mass]−1/2$

I am reading a review about supersymmetry and in page 29 I have read that the mass dimension of the Grassmann anticommuting coordinates is $-1/2$. Why this? why don't they have the same mass ...
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404 views

Elliptic genus; What is it within string/M-theory?

What is the elliptic genus (see also Witten index) in string/M-theory and (susy gauge)field theory constructions out of them? What does it tell us heuristically and what is its relation to the ...
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66 views

Some questions about Weyl spinor algebra

I am following a review on supersymmetry and I am having trouble with Weyl spinor algebra. These are equations (4.2.1) $$Q_{\alpha}=i\frac{\partial}{\partial\theta^{\alpha}}-(\sigma^{\mu}\theta^{\...
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317 views

Explicit supersymmetry breaking fermion mass terms

I hope you can clear up my following confusions. In Girardello's and Grisaru's paper (Nuclear Physics B, 194, 65 (1982)) where they analysed the most general soft explicit supersymmetry breaking ...
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137 views

Viability of a Fayet Iliopoulos term in the MSSM

Why is a Fayet-Iliopoulos term $-kD$ irrelevant or subdominant in the in the MSSM (Minimal Susy Standard Model)? According to Martin (A Supersymmetry Primer, p.70) it's because squarks and sleptons ...
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263 views

Basic question about superspace, Grassmann numbers and world sheet supersymmetry

So, I'm trying to read the section on superspace from the book on string theory by Becker, Becker and Schwarz, and I realized that I've been stuck on something simple for a while. Some relevant ...
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79 views

A question about genus one string amplitude

In BCOV's paper http://arxiv.org/abs/hep-th/9309140 the genus one string amplitude of a Calabi-Yau 3-fold was explained in the B-model as the Ray-Singer torsion (there is a similar discussion in the ...
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70 views

Supersymmetries of the type IIB D3-brane action

The following query is based on a reading of section 2.2 of a paper by Graña and Polchinski. The idea is to begin with the D3 brane action of the form $$ ds^2 = Z^{-1/2}\eta_{\mu\nu}dx^\mu dx^\nu + Z^...
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1answer
64 views

Superstring vacuum amplitude on the torus

My question is how to obtain the superstring (Type II A and B) vacuum amplitudes on a torus. They are given in Polchinski's String Theory Vol. 2 equation (10.7.9): $$Z_\psi^{\pm}=\frac{1}{2}[Z^0_0(\...
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1answer
176 views

Is time reversal symmetry broken in (conventional) superconductors?

How can one see it from BCS wavefunction and BCS Hamiltonian? i.e. $$H_{BCS}=\sum_{k\sigma}\epsilon_k c_{k\sigma}^\dagger c_{k\sigma}-\Delta^*\sum_k c_{k\uparrow}^\dagger c_{-k\downarrow}^\dagger+h....
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78 views

Kähler Potential of Calabi-Yau volume

At tree level, the Kähler potential is given by (neglecting complex structure) $K = -\ln(-\mathrm{i}(\tau - \bar{\tau})) - 2\ln(V_{CY})$ where $V_{CY} = \frac{1}{6} \kappa_{abc}t^at^bt^c$ ia the the ...
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Will the new LHC data falsify some theories? [closed]

There are plenty of extensions of the Standard Model, that all agree until the energy scales that have already been explored, but will differ at the new energy range of 14 TeV. This means the data ...
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190 views

Gauge invariance of Rarita-Schwinger action in curved spacetime

The Rarita-Schwinger action in curved $n$-dimensional spacetime is $$ \int \sqrt{g} \overline{\psi}_a \gamma^{abc} D_b \psi_c $$ Here $g = \det(g_{\mu \nu})$, and the indices $a, b \dots$ are '...
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109 views

Notation - d.o.f.'s for Grassmann delta functions in a SUSY field theory amplitude

I was reading the following paper http://arxiv.org/pdf/1306.2962v1.pdf as I stumbled upon an issue concerning counting and assigning the Grassmann degrees of freedom that appear in grassmann delta ...
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82 views

Meaning of the Coulomb and Higgs branch for non-Lagrangian theories?

What is the meaning of the Coulomb and Higgs branch for non-Lagrangian theories like the $T_N$ theories that arise as 5-brane webs and correspond to CY 3-folds in M-theory? This is related to an older ...
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78 views

Questions about the existence of 5d & 6d version of 4d ${\cal N}=2$ SCFTs

Given a 4d N=2 Superconfomal field theory (SCFT) with a global flavor symmetry ( $\mathfrak{f}$ as the corresponding lie algebra), can we clam that this theory can always flow from a 5d ${\cal N}=1$ ...