| 1. |
- Anderson, Louise, 1989, et al.
(författare)
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Tunneling solutions in topological field theory on R x S-3 x I
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2012:2, s. Article Number: 063-
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Tidskriftsartikel (refereegranskat)abstract
- We consider a topologically twisted version, recently introduced by Witten, of five-dimensional maximally supersymmetric Yang-Mills theory on a five-manifold of the form M-5 = RxW(3)xI. If the length of the interval I is sufficiently large, the supersymmetric localization equations admit pairs of static solutions (with the factor R interpreted as Euclidean time). However, these solutions disappear for a sufficiently short I, so by the topological invariance of the theory, they must be connected by an interpolating dynamic instanton solution. We study this for the case that W-3 is a three-sphere S-3 with the standard metric by making a spherically symmetric Ansatz for all fields. The solution is given as a power series in a parameter related to the length of I, and we give explicit expressions for the first non-trivial terms.
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| 2. |
- Arvidsson, Pär, 1977, et al.
(författare)
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Free tensor multiplets and strings in spontaneously broken six-dimensional (2,0) theory
- 2003
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Ingår i: Journal of High Energy Physics (JHEP). ; 06, s. 039-
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Tidskriftsartikel (refereegranskat)abstract
- We first review the representations of the six-dimensional (2,0) superalgebra on a free tensor multiplet and on a free string. We then construct a supersymmetric lagrangian describing a free tensor multiplet. (It also includes a decoupled anti self-dual part of the three-form field strength.) This field theory is then rewritten in variables appropriate for analyzing a situation where the R-symmetry is spontaneously broken by the vacuum expectation values of the scalar moduli fields. Finally, we construct a supersymmetric and κ-symmetric action for a free string.
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| 3. |
- Arvidsson, Pär, 1977, et al.
(författare)
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The (2,0) supersymmetric theory of tensor multiplets and self-dual strings in six dimensions
- 2004
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Ingår i: Journal of High Energy Physics (JHEP). ; 05, s. 048-
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Tidskriftsartikel (refereegranskat)abstract
- We construct a unique (2,0) supersymmetric action in six dimensions, describing a tensor multiplet interacting with a self-dual string. It is a sum of four terms: A free kinetic term for the tensor multiplet fields integrated over Minkowski space, a Nambu-Goto type kinetic term for the string integrated over the string world-sheet, a Wess-Zumino type electromagnetic coupling integrated over the world-volume of a Dirac membrane attached to the string, and a direct interaction of such Dirac membranes. In addition to supersymmetry, the action is also invariant under a local symmetry, which allows us to choose the Dirac membrane world-volume freely and eliminate half of the fermionic degrees of freedom on the string world-sheet.
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| 4. |
- Arvidsson, Pär, 1977, et al.
(författare)
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Thomson scattering of chiral tensors and scalars against a self-dual string
- 2002
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Ingår i: Journal of High Energy Physics (JHEP). ; 12, s. 010-
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Tidskriftsartikel (refereegranskat)abstract
- We give a non-technical outline of a program to study the (2,0) theories in six space-time dimensions. Away from the origin of their moduli space, these theories describe the interactions of tensor multiplets and self-dual spinning strings. We argue that if the ratio between the square of the energy of a process and the string tension is taken to be small, it should be possible to study the dynamics of such a system perturbatively in this parameter. As a first step in this direction, we perform a classical computation of the amplitude for scattering chiral tensor and scalar fields (i.e. the bosonic part of a tensor multiplet) against a self-dual spinnless string.
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| 5. |
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| 6. |
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| 7. |
- Henningson, Måns, 1964, et al.
(författare)
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Analysis and Modeling of Subthreshold Neural Multi-Electrode Array Data by Statistical Field Theory
- 2017
-
Ingår i: Frontiers in Computational Neuroscience. - : Frontiers Media SA. - 1662-5188. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Multi-electrode arrays (MEA) are increasingly used to investigate spontaneous neuronal network activity. The recorded signals comprise several distinct components: Apart from artefacts without biological significance, one can distinguish between spikes (action potentials) and subthreshold fluctuations (local fields potentials). Here we aim to develop a theoretical model that allows for a compact and robust characterization of subthreshold fluctuations in terms of a Gaussian statistical field theory in two spatial and one temporal dimension. What is usually referred to as the driving noise in the context of statistical physics is here interpreted as a representation of the neural activity. Spatial and temporal correlations of this activity give valuable information about the connectivity in the neural tissue. We apply our methods on a dataset obtained from MEA-measurements in an acute hippocampal brain slice from a rat. Our main finding is that the empirical correlation functions indeed obey the logarithmic behaviour that is a general feature of theoretical models of this kind. We also find a clear correlation between the activity and the occurence of spikes. Another important insight is the importance of correcly separating out certain artefacts from the data before proceeding with the analysis.
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| 8. |
- Henningson, Måns, 1964
(författare)
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Automorphic properties of (2,0) theory on T-6
- 2010
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 2010:1
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Tidskriftsartikel (refereegranskat)abstract
- We consider ADE-type (2, 0) theory on a family of flat six-tori endowed with flat Sp(4) connections coupled to the R-symmetry. Our main objects of interest are the components of the 'partition vector' of the theory. These constitute an element of a certain finite dimensional vector space, carrying an irreducible representation of a discrete Heisenberg group related to the 't Hooft fluxes of the theory. Covariance under the SL6(Z) mapping class group of a six-torus amounts to a certain automorphic transformation law for the partition vector, which we derive. Because of the absence of a Lagrangian formulation of (2, 0) theory, this transformation property is not manifest, and gives useful non-trivial constraints on the partition vector. As an application, we derive a shifted quantization law for the spatial momentum of (2, 0) theory on a space-time of the form R x T-5. This quantization law is in agreement with an earlier result based on the relationship between (2, 0) theory and maximally supersymmetric Yang-Mills theory together with certain geometric facts about gauge bundles.
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| 9. |
- Henningson, Måns, 1964, et al.
(författare)
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Bound states in N=4SYMon T-3: Spin(2n) and the exceptional groups
- 2007
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708.
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Tidskriftsartikel (refereegranskat)abstract
- The low energy spectrum of (3+1)-dimensional N = 4 supersymmetric Yang-Mills theory on a spatial three-torus contains a certain number of bound states, characterized by their discrete abelian magnetic and elecric 't Hooft fluxes. At weak coupling, the wave-functions of these states are supported near points in the moduli space of flat connections where the unbroken gauge group is semi-simple. The number of such states is related to the number of normalizable bound states at threshold in the super symmetric matrix quantum mechanics wit h 1 6 supercharges based on this unbroken group. Mathematic ally, the determination of the spectrum relies on the classification of almost commuting triples with semi-simple centralizers. We complete the work begun in a previous paper, by computing the spectrum of bound states in theories based on the even-dimensional spin groups and the exceptional groups. The results satisfy the constraints of S-duality in a rather non-trivial way.
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| 10. |
- Henningson, Måns, 1964
(författare)
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Boundary conditions for geometric-Langlands twisted N=4 supersymmetric Yang-Mills theory
- 2012
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 86:8
-
Tidskriftsartikel (refereegranskat)abstract
- We consider topologically twisted N = 4 supersymmetric Yang-Mills theory on a four-manifold of the form V = W x R+ or V = W x I, where W is a Riemannian three-manifold. Different kinds of boundary conditions apply at infinity or at finite distance. We verify that each of these conditions defines a "middle-dimensional" subspace of the space of all bulk solutions. Taking the two boundaries of V into account should thus generically give a discrete set of solutions. We explicitly find the spherically symmetric solutions when W = S-3 endowed with the standard metric. For widely separated boundaries, these consist of a pair of solutions which coincide for a certain critical value of the boundary separation and disappear for even smaller separations.
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| 11. |
- Henningson, Måns, 1964, et al.
(författare)
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BPS partition functions in N=4 Yang-Mills theory on T-4
- 2011
-
Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2011:3
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Tidskriftsartikel (refereegranskat)abstract
- We consider N = 4 Yang-Mills theory on a flat four-torus with the R-symmetry current coupled to a flat background connection. The partition function depends on the coupling constant of the theory, but when it is expanded in a power series in the R-symmetry connection around the loci at which one of the supersymmetries is unbroken, the constant and linear terms are in fact independent of the coupling constant and can be computed at weak coupling for all non-trivial 't Hooft fluxes. The case of a trivial 't Hooft flux is difficult because of infrared problems, but the corresponding terms in the partition function are uniquely determined by S-duality.
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| 12. |
- Henningson, Måns, 1964
(författare)
-
BPS states in (2,0) theory on R x T5
- 2009
-
Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2009:3
-
Tidskriftsartikel (refereegranskat)abstract
- We consider (2, 0) theory on a space-time of the form R x T(5), where the first factor denotes time, and the second factor is a flat spatial five-torus. In addition to their energy, quantum states are characterized by their spatial momentum, 't Hooft flux, and Sp(4) R-symmetry representation. The momentum obeys a shifted quantization law determined by the 't Hooft flux. By supersymmetry, the energy is bounded from below by the magnitude of the momentum. This bound is saturated by BPS states, that are annihilated by half of the supercharges. The spectrum of such states is invariant under smooth deformations of the theory, and can thus be studied by exploiting the interpretation of (2, 0) theory as an ultra-violet completion of maximally supersymmetric Yang-Mills theory on R x T(4). Our main example is the A-series of (2, 0) theories, where such methods allow us to study the spectrum of BPS states for many values of the momentum and the 't Hooft flux. In particular, we can describe the R-symmetry transformation properties of these states by determining the image of their Sp(4) representation in a certain quotient of the Sp(4) representation ring.
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| 13. |
- Henningson, Måns, 1964
(författare)
-
Börja med kvantfysik
- 2018
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Börja med kvantfysik syftar till att ge en klar och koncis introduktion till kvantfysikens begreppsvärld. Detta är av stor betydelse för att förstå det mesta av både tidigare och framtida fysikforskning och många spännande teknologiska tillämpningar. Framställningen är inspirerad av kvantfysikens matematiska struktur som vi förstår den i dag snarare än av den historiska utvecklingen. Betoningen ligger på allmänna principer, vilket ger läsaren verktyg för att sedan analysera vitt skilda fysikaliska problem. Kvantfysiken uppfattas ofta som svårbegriplig, och än i dag utmanar den många av våra invanda föreställningar om världen. Samtidigt bygger den till största delen på väletablerad matematik och har en glasklar logisk struktur. Börja med kvantfysik utnyttjar detta för att ge en systematisk introduktion till ämnet. Den allmänna teorin illustreras med pedagogiska exempel, och ett flertal övningar med svar ger tillfällen till egen träning. Börja med kvantfysik är anpassad till läsare som tillgodogjort sig grundläggande matematik och fysik på högskolenivå. Den kan användas som undervisningsmaterial på en första kurs i kvantfysik, och är också väl lämpad för självstudier.
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| 14. |
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| 15. |
- Henningson, Måns, 1964, et al.
(författare)
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Dyonic anomalies
- 2005
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 267:1-4, s. 203-207
-
Tidskriftsartikel (refereegranskat)abstract
- We consider the problem of coupling a dyonic p-brane in d = 2p + 4 space-time dimensions to a prescribed (p + 2)-form field strength. This is particularly subtle when p is odd. For the case p = 1, we explicitly construct a coupling functional, which is a sum of two terms: one which is linear in the prescribed field strength, and one which describes the coupling of the brane to its self-field and takes the form of a Wess-Zummo term depending only on the embedding of the brane world-volume into space-time. We then show that this functional is well-defined only modulo a certain anomaly, related to the Euler class of the normal bundle of the brane world-volume.
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| 16. |
- Henningson, Måns, 1964
(författare)
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Ground states of supersymmetric Yang-Mills-Chern-Simons theory
- 2012
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; 1211:11, s. 013-
-
Tidskriftsartikel (refereegranskat)abstract
- We consider minimally supersymmetric Yang-Mills theory with a Chern-Simons term on a flat spatial two-torus. The Witten index may be computed in the weak coupling limit, where the ground state wave-functions localize on the moduli space of flat gauge connections. We perform such computations by considering this moduli space as an orbifold of a certain flat complex torus. Our results agree with those obtained previously by instead considering the moduli space as a complex projective space. An advantage of the present method is that it allows for a more straightforward determination of the discrete electric 't Hooft fluxes of the ground states in theories with non-simply connected gauge groups. A consistency check is provided by the invariance of the results under the mapping class group of a (Euclidean) three-torus.
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| 17. |
- Henningson, Måns, 1964, et al.
(författare)
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Holography and the Weyl anomaly
- 2000
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Ingår i: Fortsch. Phys.. ; 48, s. 125-
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Tidskriftsartikel (refereegranskat)
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| 18. |
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| 19. |
- Henningson, Måns, 1964, et al.
(författare)
-
Low-energy spectrum of N=4 super-Yang-Mills on T-3: flat connections, bound states at threshold, and S-duality
- 2007
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708.
-
Tidskriftsartikel (refereegranskat)abstract
- We study (3+1)-dimensional N = 4 supersymmetric Yang-Mills theory on a spatial three-torus. The low energy spectrum consists of a number of continua of states of arbitrarily low energies. Although the theory has no mass-gap, it appears that the dimensions and discrete abelian magnetic and electric 't Hooft fluxes of the continua are computable in a semi-classical approximation. The wave-functions of the low-energy states are supported on submanifolds of the moduli space of flat connections, at which various subgroups of the gauge group are left unbroken. The field theory degrees of freedom transverse to such a submanifold are approximated by supersymmetric matrix quantum mechanics with 16 supercharges, based on the semi-simple part of this unbroken group. Conjectures about the number of normalizable bound states at threshold in the latter theory play a crucial role in our analysis. In this way, we compute the low-energy spectrain the cases where the simply connected cover of the gauge group is given by SU(n), Spin(2n+1) or Sp(2n). We then show that the constraints of S-duality are obeyed for unique values of the number of bound states in the matrix quantum mechanics. In the cases based on Spin(2n+1) and Sp(2n), the proof involves surprisingly subtle combinatorial identities, which hint at a rich underlying structure.
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| 20. |
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| 21. |
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| 22. |
- Henningson, Måns, 1964
(författare)
-
Six-dimensional (2,0) theory on tori
- 2013
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 462:1
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Konferensbidrag (refereegranskat)abstract
- The six-dimensional (2,0) theories are a comparatively new and rather abstract type of quantum theory with important relations both to supersymmeric Yang-Mills theory in lower dimensions and to string- and M-theory in higher dimensions. After a short introduction to these theories, we focus on the case when they are considered on flat tori [1] [2]. In particular, we give an example of how their ground state degeneracies can be computed, and also briefly discuss the spectrum of BPS-states. Finally, we comment on the automorphic transformation properties of the partition function of such a theory under the mapping class group of a six-torus.
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| 23. |
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| 24. |
- Henningson, Måns, 1964
(författare)
-
't Hooft operators in the boundary
- 2011
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 84:10
-
Tidskriftsartikel (refereegranskat)abstract
- We consider a topologically twisted maximally supersymmetric Yang-Mills theory on a four-manifold of the form V = W x R(+). 't Hooft disorder operators localized in the boundary component at finite distance of V are relevant for the study of knot theory on the three-manifold W and have recently been constructed for a gauge group of rank one. We extend this construction to an arbitrary gauge group G. For certain values of the magnetic charge of the 't Hooft operator, the solutions are obtained by embedding the rank-one solutions in G and can be given in closed form.
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| 25. |
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| 26. |
- Henningson, Måns, 1964
(författare)
-
The low-energy spectrum of (2,0) theory on T5 x R
- 2008
-
Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2008:11, s. 028-
-
Tidskriftsartikel (refereegranskat)abstract
- We consider the ADE-series of (2, 0) supersymmetric quantum theories on T(5) x R, where the first factor is a flat spatial five-torus, and the second factor denotes time. The quantum states of such a theory Phi are characterized by a discrete quantum number f is an element of H(3)(T(5), C), where the finite abelian group C is the center subgroup of the corresponding simply connected simply laced Lie group G. At energies that are low compared to the inverse size of the T5, the spectrum consists of a set of continua of states, each of which is characterized by the value of f and some number 5r of additional continuous parameters. By exploiting the interpretation of this theory as the ultraviolet completion of maximally supersymmetric Yang-Mills theory on T(4) x S(1) x R with gauge group G(adj) = G/C and coupling constant g given by the square root of the radius of the S(1) factor, one may compute the number N(f)(r) (Phi) of such continua. We perform these calculations in detail for the A- and D-series. While the Yang-Mills theory formalism is manifestly invariant under the SL(4)(Z) mapping class group of T(4), the results are actually found to be invariant under the SL(5)(Z) mapping class group of T(5), which provides a strong consistency check.
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| 27. |
- Henningson, Måns, 1964
(författare)
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The partition bundle of type AN-1 (2, 0) theory
- 2011
-
Ingår i: Journal of High Energy Physics. - 1029-8479 .- 1126-6708.
-
Tidskriftsartikel (refereegranskat)abstract
- Six-dimensional (2, 0) theory can be defined on a large class of six-manifolds endowed with some additional topological and geometric data (i.e. an orientation, a spin structure, a conformal structure, and an R-symmetry bundle with connection). We discuss the nature of the object that generalizes the partition function of a more conventional quantum theory. This object takes its values in a certain complex vector space, which fits together into the total space of a complex vector bundle (the 'partition bundle') as the data on the six-manifold is varied in its infinite-dimensional parameter space. In this context, an important role is played by the middle-dimensional intermediate Jacobian of the six-manifold endowed with some additional data (i.e. a symplectic structure, a quadratic form, and a complex structure). We define a certain hermitian vector bundle over this finite-dimensional parameter space. The partition bundle is then given by the pullback of the latter bundle by the map from the parameter space related to the six-manifold to the parameter space related to the intermediate Jacobian.
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| 28. |
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| 29. |
- Henningson, Måns, 1964, et al.
(författare)
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Weyl anomaly for Wilson surfaces
- 1999
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Ingår i: Journal of high energy physics. ; 9906, s. 012-
-
Tidskriftsartikel (refereegranskat)
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| 30. |
- Henningson, Måns, 1964
(författare)
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What is the Partition Bundle?
- 2012
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Ingår i: Physics of Particles and Nuclei. - 1063-7796. ; 43:5, s. 621-624
-
Tidskriftsartikel (refereegranskat)abstract
- Six-dimensional (2, 0) theory can be defined on a large class of six-manifolds endowed with some additional topological and geometrical data. We discuss the nature of the object in such a theory that generalizes the partition function of a more conventional quantum field theory.
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| 31. |
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| 32. |
- Henningson, Måns, 1964, et al.
(författare)
-
Zero-energy bound states of N=4 SYM on T^3: S-duality and the mapping class group
- 2008
-
Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 0804:4, s. 066-
-
Tidskriftsartikel (refereegranskat)abstract
- We continue our studies of the low-energy spectrum of N = 4 super-Yang-Mills theory on a spatial three-torus. In two previous papers, we computed the spectrum of normalizable zero-energy states for all choices of gauge group and all values of the electric and magnetic 't Hooft fluxes, and checked its invariance under the SL2(Z) S-duality group. In this paper, we refine the analysis by also decomposing the space of bound states into irreducible unitary representations of the SL3(Z) mapping class group of the three-torus. We perform a detailed study of the S-dual pairs of theories with gauge groups Spin(2n+1) and Sp(2n). The predictions of S-duality (which commutes with the mapping class group) are fulfilled as expected, but the proof requires some surprisingly intricate combinatorial infinite product identities.
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| 33. |
- Henningson, Måns, 1964
(författare)
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Zero-mode dynamics in supersymmetric Yang-Mills-Chern-Simons theory
- 2013
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 87:10
-
Tidskriftsartikel (refereegranskat)abstract
- We consider minimally supersymmetric Yang-Mills theory with a Chern-Simons term on a flat spatial two-torus in the limit when the torus becomes small. The zero modes of the fields then decouple from the nonzero modes and give rise to a spectrum of states with energies that are given by multiples of the square of the coupling constant. We discuss the determination of this low-energy spectrum, both for simply connected gauge groups and for gauge groups of adjoint type, with a few examples worked out in detail.
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| 34. |
- Wahlsten, Olov, 1989, et al.
(författare)
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Quantitative Detection of Biological Nanoparticles in Solution via Their Mediation of Colocalization of Fluorescent Liposomes
- 2019
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Ingår i: Physical Review Applied. - 2331-7019. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Detection of biomolecules and biological nanoparticles by means of induced aggregation of larger nanoparticles using light scattering as readout was first accomplished in the middle of the last century. Since then, technical advances together with novel nanomaterials have enabled more sophisticated readout schemes, paving the way for methods exploiting dual-probe hybridization for biomolecular or nonoparticle recognition that today can compete with established bioanalytical methods. Herein, we present a quantitative assay, with single-nanoparticle readout, utilizing receptor-containing cell-membrane mimics in the shape of approximately 100-nm lipid liposomes rather than conventional antibody-modified nanoparticles to enable detection of virus particles in solution. Specifically, the method is based on virus-mediated aggregation of differently fluorescent-labeled liposomes that contain the ganglioside GM1 receptor for the Simian Virus 40 (SV40). The aggregation kinetics of the differently colored liposomes is studied by monitoring the spatial colocalization level of the liposomes and a theoretical model that successfully represents aggregation kinetics versus virus concentration is proposed. The limits of detection are identified experimentally for our current setup and theoretically in a more general context. The consistency between theory and experiments suggests that the approach will be generically applicable for similar biosensing applications or for the study of related systems where natural interactions with cell-membrane components can be used to induce liposome aggregation.
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