The supersymmetry tag has no wiki summary.
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Hamiltonian in SUSY (SUSY algebra)
I was reading the book Supersymmetry, Theory, Experiment and Cosmology by P. Binétruy, and on page 25 the author goes from
$$ 1)[Q_r,Q_t]_+ \gamma^{0}_{ts}=2\gamma^{\mu}_{rs}P_{\mu} $$ $$ ...
1
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1answer
85 views
Differences between Goldstone bosons and fermions
I have been looking into basic SUSY and SUGRA theory and have a question relating to Goldstinos (particles giving gravitinos mass).
Simply are these analogous to Goldstone bosons produced in the ...
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sigma model on $S^1 \times S^3$
In arXiv:1207.3497 - 4D partition function on $S^1 \times S^3$ and 2D Yang-Mills with nonzero area, Yuji Tachikawa explains the partition function for an 4d $\mathcal{N}=2$ sigma model on $S^3 \times ...
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2answers
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What is the current status of string theory (2013)?
I've seen a bunch of articles talking about how new findings from the LHC seem to disprove (super)string theory and/or supersymmetry, or at least force physicists to reformulate them and change ...
10
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1answer
226 views
Witten's constrained S-matrix and Coleman-Mandula Theorem
I remember reading somewhere that Witten argued that if the Poincaré symmetry of spacetime were nontrivially combined with internal symmetries, then the S-matrix would be so constrained that the ...
2
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1answer
61 views
Induce a Fayet-Iliopoulos term
In a supersymmetric U(1) gauge theory, if I leave off the Fayet-Iliopoulos term $\kappa [V]_D$, what keeps it from being induced in loop corrections?
5
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1answer
91 views
CP-violation in SUSY QED?
I have just gone through the exercise of constructing the supersymmetrized QED action.
In the end, I get a reasonable action which matches literature. But after a little analysis, I find that the ...
1
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2answers
278 views
Mathematically: What is SUSY?
Wikipedia says:
In particle physics, supersymmetry (often abbreviated SUSY) is a symmetry that relates elementary particles of one spin to other particles that differ by half a unit of spin and ...
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How to perform contour integral in Nekrasov's formula
My question is technical. It is about instanton counting calculation (see this paper).
The partition function of SU(N) gauge theory with $N_f$ fundamental multiplets in k instanton background is ...
2
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0answers
57 views
Why/When can the gauge superfield and/or chiral superfield kinetic term in $(2,2)$ SUSY be ignored?
This is in reference to the argument given towards the end of page $61$ of this review paper. There for the path-integral argument to work the author clearly needed some argument to be able to ignore ...
9
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3answers
199 views
On-shell symmetry from a path integral point of view
Normally supersymmetric quantum field theories have Lagrangians which are supersymmetric only on-shell, i.e. with the field equations imposed. In many cases this can be solved by introducing auxilary ...
7
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1answer
193 views
Canonical quantization in supersymmetric quantum mechanics
Suppose you have a theory of maps
$\phi: {\cal T} \to M$
with $M$ some Riemannian manifold,
Lagrangian
$$L~=~ \frac12 g_{ij}\dot\phi^i\dot\phi^j + \frac{i}{2}g_{ij}(\overline{\psi}^i ...
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52 views
Supersymmetric Sigma Model
I was working through the Mirror Symmetry book by Clay Math Institute. It deals with supersymmetric sigma model in 10.4 section. It doesn't derive how the action is invariant under the variation. I am ...
4
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1answer
74 views
$\pm$ (light-cone?) notation in supersymmetry
I would like to know what is exactly meant when one writes $\theta^{\pm}, \bar{\theta}^\pm, Q_{\pm},\bar{Q}_{\pm},D_{\pm},\bar{D}_{\pm}$.
{..I typically encounter this notation in literature on ...
5
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2answers
103 views
Why aren't the spin-3/2 fields in the (3/2,0)+(0,3/2) representation?
Why is it that spin-$\frac 32$ fields are usually described to be in the $(\frac 12, \frac 12)\otimes[(\frac 12,0)\oplus(0,\frac 12)]$ representation (Rarita-Schwinger) rather than the $(\frac ...
5
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1answer
95 views
Renormalization of the R-charge?
In general I would like to know as to known or what is/are the standard references about R-charge renormalization in supersymmetric theories. When does it do so and what is expected or known to be ...
1
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1answer
108 views
Divergence in Supergravity
I'm not familiar with supergravity so here's my question: I've heard in talks that if one finds divergence for five-loop 4-graviton scattering amplitudes in five dimensions this translates to a ...
6
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1answer
131 views
Where does the hidden supersymmetric sector of the MSSM come from?
At the end of Chapter 14 of the "Supersymmetry Demystified book" from Patrick Labelle it is mentioned that to constrain the number of allowed softly SUSY breaking terms, a shadow or hidden ...
6
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1answer
97 views
Status of the little hierarchy problem
What is the current thinking on the little hierarchy problem in light of a potential Higgs mass above 120 GeV? A few years ago, at least, I remember various phenomenologists saying that this at least ...
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1answer
97 views
Why does unbroken supersymmetry imply the absence of tachyons?
Just a quick question, same as in the title. I'm trying to understand stable D-branes.
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Can mass dimension of a field be viewed as another 'quantum number'?
While studying SUSY in 4D, I noticed the dynamical chiral superfield has dimension [GeV], whereas the dynamical vector superfield (for gauge theories) is unitless. Because I was introduced to the ...
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0answers
51 views
Are irrelevant terms in the Kahler potential always irrelevant, even at strong coupling?
I've been reading about the duality cascade in Strassler's TASI '03 lectures (hep-th/0505153). He reminds us of the non-renormalization theorem theorem for the superpotential so that the beta ...
3
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1answer
77 views
Pauli-Villars (PV) regularisation breaks supersymmetry. How to see that?
Does the PV regulator breaks SUSY?
Take for instance the 1-loop (top/stop loops) correction to the Higgs squared-mass parameter in the MSSM, and you'll get something like,
$$\delta m^2_{h_u} = - ...
5
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0answers
82 views
Auxiliary fields in supersymmetry
I know that auxiliary fields can be used to close the supersymmetry algebra in case the bosonic and fermionic on-shell degrees of freedom do not match. Could somebody please elaborate on this concept ...
4
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1answer
106 views
$U(1)$ beta function of low energy effective Seiberg-Witten theory
My question is about figure3 (page 8) of this paper
hep-th/9705131.
Start from Seiberg-Witten theory, integrate out the charged
high energy modes down to Higgs scale and we get a $U(1)$ gauge
theory ...
8
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1answer
86 views
What evidence do we have for S-duality in N=4 Super-Yang-Mills?
Do we have anything resembling a proof*? Or is it just a collection of "coincidences"?
Also, do we have evidence from lattice gauge theory computations?
*Of course I'm not talking about a proof in ...
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2answers
175 views
How to prove quantum N=4 Super-Yang-Mills is superconformal?
I'm especially interested in elegant illuminating proofs which don't involve a lot of straightforward technical computations
Also, does a non-perturbative proof exist?
2
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1answer
118 views
Construction of the supersymmetric Faraday tensor
When I first learned gauge theories in my introductory quantum field theory course, I was taught that the Faraday (field-strength) tensor can be constructed by computing the commutator of the ...
16
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2answers
308 views
Kähler potential vs full effective potential
In evaluating the vacuum structure of quantum field theories you need to find the minima of the effective potential including perturbative and nonperturbative corrections where possible.
In ...
12
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2answers
165 views
Generalized Complex Geometry and Theoretical Physics
I have been wondering about some of the different uses of Generalized Complex Geometry (GCG) in Physics. Without going into mathematical detail (see Gualtieri's thesis for reference), a Generalized ...
5
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1answer
25 views
Scaling solutions in context of Denef - Moore
My question is based on the paper Split states, entropy enigma, holes, halos.
What are the scaling solutions discussed on page 49 of the paper ?
It is stated that the equations ${\sum_{j, i\neq ...
12
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1answer
50 views
Local Fermionic Symmetry
That is perhaps a bit of an advertisement, but a couple of collaborators and myself just sent out a paper, and one of the results there is a little bit surprising. We found (in section 6E) a fermionic ...
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2answers
160 views
Values of SM parameters at one certain scale
The general question is:
What are the values of Standard Model parameters (in the $\bar{MS}$ renormalization scheme) at some scale e.g. $m_{Z}$? As its parametrization in Yukawa matrices is not unique ...
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Uniqueness of supersymmetric heterotic string theory
Usually we say there are two types of heterotic strings, namely $E_8\times E_8$ and $Spin(32)/\mathbb{Z}_2$. (Let's forget about non-supersymmetric heterotic strings for now.)
The standard argument ...
4
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2answers
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What constitutes a 'reliable' instanton calculation?
In Modern Supersymmetry, John Terning, on pgs 151, and 153 performs a so called 'reliable' instanton calculation when dealing with the ADS superpotential 'since the gauge group is completely broken'. ...
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3answers
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Paper listing known Seiberg-dual pairs of N=1 gauge theories
Is there a nice list of known Seiberg-dual pairs somewhere? There are so many papers from the middle 1990s but I do not find comprehensive review. Could you suggest a reference?
Seiberg's original ...
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1answer
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Dual Pairs in Four Dimensions
Following the conversation here, I am wondering if anyone knows of an example of dual pair with 4-dimensional N=1 SUSY which relates a non-Abelian gauge theory on one side to a theory with a ...
18
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2answers
131 views
Does 4D N = 3 supersymmetry exist?
Steven Weinberg's book "The Quantum Theory of Fields", volume 3, page 46 gives the following argument against N = 3 supersymmetry:
"For global N = 4 supersymmetry there is just one supermultiplet ... ...
21
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1answer
190 views
Vassiliev Higher Spin Theory and Supersymmetry
Recently there is renewed interest in the ideas of Vassiliev, Fradkin and others on generalizing gravity theories on deSitter or Anti-deSitter spaces to include higher spin fields (utilizing known ...
4
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1answer
121 views
Limit on space-time dimension from susy
I read an argument saying that it would be impossible to write down a super-symmetric theory in more than 11 dimensions, this limit coming from the dimension of the Clifford algebra that goes as ...
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2answers
187 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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1answer
93 views
What are “hidden valley sectors”?
In this end of the year article, Prof. Strassler mentioned that hidden valley sectors could lead to some still open loopholes concerning the experimental discovery of supersymmetry and other BSM ...
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2answers
51 views
“tmf(n) is the space of supersymmetric conformal field theories of central charge -n”
I read this intriguing statement in John Baez' week 197 the other day, and I've been giving it some thought. The post in question is from 2003, so I was wondering if there has been any progress in ...
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Higgs boson and string theory
Assuming Higgs is found at 125 GeV.Is there any direct or indirect consequence on string theory ? Will it be a blow to string theory or models employing string theory ?
...
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404 views
On the Coulomb branch of N=2 supersymmetric gauge theory
The chiral ring of the Coulomb branch of a 4d N=2 supersymmetric gauge theory is given by the Casimirs of the vector multiplet scalars, and they don't have non-trivial relations; the Casimirs are ...
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39 views
Linear combination of anomalous dimensions in effective potential on pseudomoduli space
In the paper of Intriligator, Seiberg, and Shih from 2007, they give an expression for the effective potential on the pseudo-moduli space $X$, estimated at large $X$ (equation 1.3).
In this equation, ...
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1answer
152 views
What exactly are super WIMPs?
I recently got confused (and slightly annoyed by the lack of technical details) when reading a popular article (authored by Jonathan Feng and Mark Trodden) introducing the concept of super WIMPs.
The ...
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1answer
98 views
How to handle Yukawa contractions in calculating SUSY beta functions?
I'm reading Chapter 6 of Martin's introduction to SUSY http://arxiv.org/abs/hepph/9709356, which is about RGEs in the MSSM. I tried to convince myself of some of the calculations, and I was ...
8
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1answer
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“finite” QFTs and short-distance singularities and vanishing beta functions
I am not sure that I can frame this question coherently enough - it springs from various things in QFT that I have recently been thinking and reading about. May be these thoughts are mis-directed but ...
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93 views
What is non-Abelian about non-Abelian Chern-Simons' theory?
One is aware that in the axial gauge (say the light-cone gauge $A_{-}=0$) non-supersymmetric Chern-Simons' theory is a quadratic theory. Hence in this gauge there are no gauge-gauge interactions. Then ...
