Seminars and Events: Fall 2013
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 August 2013

Joint DISCOVERYHET Seminar
Aud. A, Thursday 8 Aug at 14:15
Rajamani Narayanan (Florida International University)
Phase structure of twodimensional QED at zero temperature with flavordependent chemical potentials and the role of multidimensional theta functionsJoint DISCOVERYHET Seminar
Rajamani Narayanan
Phase structure of twodimensional QED at zero temperature with flavordependent chemical potentials and the role of multidimensional theta functions
Abstract:
We consider QED on a twodimensional Euclidean torus with $f$ flavors of massless fermions and flavordependent chemical potentials. The dependence of the partition function on the chemical potentials is reduced to a $(2f2)$dimensional theta function. At zero temperature, the system can exist in an infinite number of phases characterized by certain values of traceless number densities and separated by firstorder phase transitions. Furthermore, there exist many points in the $(f1)$dimensional space of traceless chemical potentials where two or three phases can coexist for $f=3$ and two, three, four or six phases can coexist for $f=4$. We conjecture that the maximal number of coexisting phases grows exponentially with increasing $f$.
Details
Date: Thursday 8 Aug
Time: 14:15
Place: Aud. A
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× 
Conference: Current Themes in High Energy Physics and Cosmology
NBI, Sunday 11 Aug  Monday 19 Aug at
Conference: Current Themes in High Energy Physics and Cosmology
Current Themes in High Energy Physics and Cosmology
Abstract:
More info: https://indico.nbi.ku.dk/conferenceDisplay.py?confId=536
Details
Date: Sunday 11 Aug  Monday 19 Aug
Time:
Place: NBI
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× 
NBIA Colloquium
Aud. A, Tuesday 20 Aug at 14:15
Itamar Procaccia (Weizmann Institute of Science)
Numbers in Nature, Art and ArchitectureNBIA Colloquium
Itamar Procaccia
Numbers in Nature, Art and Architecture
Abstract:
In this lecture I will review the evolution of the concept of numbers in the ages as they appear in language, in Nature, in Art and in Architecture.
Details
Date: Tuesday 20 Aug
Time: 14:15
Place: Aud. A
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× 
Joint DISCOVERYHET Seminar
Aud. A, Thursday 29 Aug at 14:15
Alessandro Strumia (CERN)
Naturalness after LHC Run 1Joint DISCOVERYHET Seminar
Alessandro Strumia
Naturalness after LHC Run 1
Abstract:
LHC results did not confirm the theoretical expectations based on naturalness. We summarize the present status of this issue, and explore the possibility that the usual criterion for naturalness by ignoring the uncomputable power divergences.
Details
Date: Thursday 29 Aug
Time: 14:15
Place: Aud. A
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×  September 2013

Niels Bohr Lecture
Aud. 3 @ HCØ, Wednesday 4 Sep at 16:15
Subir Sarkar
Connecting inner space & outer spaceNiels Bohr Lecture
Subir Sarkar
Connecting inner space & outer space
Abstract:
We have just celebrated the centenary of the finding that the Earth is being constantly bombarded by high energy `cosmic rays' from space. This initiated a glorious era of discovery of many new particles (positron, muon, pion, ...) and developed into acceleratorbased research into high energy physics. A century later this has given us the triumphant `Standard Model' of particle physics which provides a precise quantum description of all fundamental processes in terrestrial laboratories, including (with the recent discovery of "a Higgs boson") an understanding of how particles acquire mass.
Unfortunately the Standard Model does not explain any of the salient features of the universe as a whole  Why there is matter but no antimatter? Why there is so much more `dark matter' of unknown origin? Why is the expansion rate apparently accelerating, as if driven by a Cosmological Constantlike, dominant component of `dark energy'?
In this lecture I will describe how new kinds of experiments and theoretical developments at the rapidly growing interface of astroparticle physics are attempting to answer these cosmic questions, by linking them to possible new physics that lies beyond the Standard Model.
More info: http://www.nbi.ku.dk/Besoeg_os/niels_bohr_lectures/2013/subir_sarker/
Details
Date: Wednesday 4 Sep
Time: 16:15
Place: Aud. 3 @ HCØ
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× 
Joint DISCOVERYHET Seminar
Aud. A, Tuesday 10 Sep at 14:15
Agnese Bissi
Higher spin correlatorsJoint DISCOVERYHET Seminar
Agnese Bissi
Higher spin correlators
Abstract:
In this talk I will discuss the threepoint correlator of two protected scalar operators and one higher spin twisttwo operator in N = 4 SYM, in the limit of large spin. This structure constant can be extracted from the OPE of the fourpoint correlator of protected scalar operators. Based on the OPE structure, symmetry arguments and intuition from the available perturbative results, it is possible to predict the structure constant at all loops in perturbation theory. This allows also to propose an expression for the all loops fourpoint correlator in a particular limit.
Details
Date: Tuesday 10 Sep
Time: 14:15
Place: Aud. A
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× 
Joint DISCOVERYHET Seminar
Aud. A, Thursday 12 Sep at 14:15
Johannes Broedel (ETH Zurich)
Polylogarithms, Multiple Zeta Values, Worldsheet Integrals and the Drinfeld AssociatorJoint DISCOVERYHET Seminar
Johannes Broedel
Polylogarithms, Multiple Zeta Values, Worldsheet Integrals and the Drinfeld Associator
Abstract:
Openstring treelevel amplitudes have been calculated from worldsheet integrals using a variety of techniques during the last decades. I am going to discuss, how polylogarithms can be employed to formalize the calculation, which in turn allows to calculate those amplitudes for any multiplicity and to any order in the inverse string tension. Starting from these results, I will describe an Smatrix shortcut: employing algebraic methods utilizing the Drinfeld associator, all treelevel openstring amplitudes can be obtained recursively without solving a single worldsheet integral.
Details
Date: Thursday 12 Sep
Time: 14:15
Place: Aud. A
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× 
PhD defense
Aud. A, Friday 13 Sep at 10:00
Martin Hansen
Anomalies of the Cosmic Microwave BackgroundPhD defense
Martin Hansen
Anomalies of the Cosmic Microwave Background
Abstract:
More info: http://het.nbi.dk/Events/13b/PHDHansen.html
Details
Date: Friday 13 Sep
Time: 10:00
Place: Aud. A
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× 
MSc defense
Aud. A, Tuesday 17 Sep at 11:00
Morten H. Christensen
Aspects of Lifshitz HolographyMSc defense
Morten H. Christensen
Aspects of Lifshitz Holography
Abstract:
In recent years, extensions of the AdS/CFT correspondence have opened up the possibility of studying condensed matter systems using holography. Here we will consider z = 2 Lifshitz spacetimes in 4 dimensions as possible duals of 3dimensional nonrelativistic condensed matter systems exhibiting anisotropic scaling, and construct a framework in which the sources can be identied and the vevs calculated. The basis for this construction will be the fact that z = 2 Lifshitz spacetimes in 4 dimensions are related to AlAdS spacetimes by ScherkSchwarz reduction.
In the defense, I will briey review the holographic principle and its rst realization, namely the AdS/CFT correspondence. I then proceed to discuss the dimensional reduction of 5dimensional AdS spaces and show that this leads to 4dimensional Lifshitz spaces. The constraints imposed such that the 4dimensional theory is Asymptotically locally Lifshitz are reviewed and I argue that a deformation is required in order to calculate the vevs of the boundary theory. Various irrelevant deformations are considered and new classes of spacetimes, namely the generalized AlLif and Lifshitz UV, are dened. It is shown that the
boundary geometry of these spacetimes is that of Newton{Cartan with torsion. Furthermore, we dene ALif spacetimes whose boundary geometry is pure Newton{Cartan. Within the Lifshitz UV spacetime the sources of the 4dimensional theory are analyzed. Due to the consistency of the reduction, the 4dimensional vevs can be written entirely in terms of the 5dimensional vevs. This fact is used to calculate the stressenergy tensor of the boundary theory. Furthermore, we nd six Ward identities constraining the vevs of the boundary theory and use these to argue for a definition of a gauge invariant stressenergy tensor.
More info: http://het.nbi.dk/Events/13b/MScChristensen.html
Details
Date: Tuesday 17 Sep
Time: 11:00
Place: Aud. A
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× 
Discovery Colloquium
Aud A, Tuesday 17 Sep at 14:15
Veronica Sanz (Sussex)
The Higgs is here, and now what?Discovery Colloquium
Veronica Sanz
The Higgs is here, and now what?
Abstract:
In this colloquium we will discuss the recent discovery of the Higgs particle. We will review the current understanding of its properties, and the prospects of using Higgs data to learn about new principles in Nature. We will explain how Supersymmetry, new strong dynamics, and other proposals for beyond the Standard Model can be probed making use of this data. We will finish with an overview of what is the next frontier in the experimental Higgs program.
Details
Date: Tuesday 17 Sep
Time: 14:15
Place: Aud A
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× 
Joint HETDiscovery seminar
Aud A, Thursday 19 Sep at 14:15
David Skinner (Cambridge)
Twistor Strings for N=8 SupergravityJoint HETDiscovery seminar
David Skinner
Twistor Strings for N=8 Supergravity
Abstract:
I'll explain a new way of looking at 4d supergravity  as a theory of holomorphic maps into Penrose's twistor space. Allowing twistor space to have N fermionic directions, the theory is anomaly free when N=8. Via the Penrose transform, the vertex operators correspond to an N=8 Einstein supergravity multiplet. Conformal symmetry is explicitly broken by the presence of the infinity twistor in the BRST operator. The complete classical Smatrix is recovered from worldsheet correlation functions and interpreted geometrically. Time permitting, I will explain what I know of the model at higher genus.
Details
Date: Thursday 19 Sep
Time: 14:15
Place: Aud A
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× 
Twominute meeting
Aud. A , Tuesday 24 Sep at 14:15
Twominute meeting
Abstract:
More info: http://het.nbi.dk/Events/13b/twominute2013.html
Details
Date: Tuesday 24 Sep
Time: 14:15
Place: Aud. A
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× 
Niels Bohr Lecture
Aud. 3 @ HCØ, Wednesday 25 Sep at 15:15
Priyamvada Natarajan (Yale University)
From seeds to behemoths: tracking the formation of supermassive black holes in the universeNiels Bohr Lecture
Priyamvada Natarajan
From seeds to behemoths: tracking the formation of supermassive black holes in the universe
Abstract:
Populations of quasars powered by accretion onto SMBHs with masses in excess of 10^9 solar masses are now detected when the Universe was barely a Gyr old. And in the local universe the centers of several nearby brightest cluster galaxies harbor behemoths that weigh ~ a few times 10^10 solar masses.
I will discuss how these monster black holes likely form and what observational signatures can test the various formation & growth scenarios. Aside from outlining the current status of our understanding, I will close with the open exciting questions and challenges ahead for theory given the wealth of observational data in hand and in the pipeline.
More info: http://www.nbi.ku.dk/Besoeg_os/niels_bohr_lectures/2013/priyamvada_natarajan2/
Details
Date: Wednesday 25 Sep
Time: 15:15
Place: Aud. 3 @ HCØ
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× 
Joint DISCOVERYHET Seminar
Aud. A, Thursday 26 Sep at 14:15
Claudio Pica (CP3Origins, University of Southern Denmark)
Studies of Minimal Walking Technicolor on the latticeJoint DISCOVERYHET Seminar
Claudio Pica
Studies of Minimal Walking Technicolor on the lattice
Abstract:
Minimal Walking Technicolor (MWT) models have been proposed to explain the mechanism for Electroweak symmetry breaking by replacing the fundamental Higgs particle with a new strongly interacting sector, in which the Higgs is composite. In view of the recent discovery of the Higgs particle and the experimental searches for MWT by the ATLAS collaboration, it is relevant to understand MWT models quantitatively in more detail. I will present some of our recent lattice studies of two MWT models, the SU(2)a and the SO(4)v models, aimed at determining the details of the strong dynamics and provide inputs for the experimental searches.
Details
Date: Thursday 26 Sep
Time: 14:15
Place: Aud. A
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×  October 2013

HET journal club lunch
Fb6, Wednesday 2 Oct at 12:30
HET journal club lunch
Startup meeting
Abstract:
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Date: Wednesday 2 Oct
Time: 12:30
Place: Fb6
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× 
HET journal club seminar
Fb6, Wednesday 2 Oct at 13:15
Gianluca Grignani
Thermal DBI at weak and strong couplingHET journal club seminar
Gianluca Grignani
Thermal DBI at weak and strong coupling
Abstract:
Details
Date: Wednesday 2 Oct
Time: 13:15
Place: Fb6
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× 
PhD Defense
Aud. A, Thursday 3 Oct at 14:00
Jakob Gath
Hydrodynamics and Elasticity of Charged Black BranesPhD Defense
Jakob Gath
Supervisor: Niels Obers
Hydrodynamics and Elasticity of Charged Black Branes
Abstract:
We consider longwavelength perturbations of charged black branes to first order in a fluidelastic derivative expansion. At first order the perturbations decouple and we treat the hydrodynamic and elastic perturbations separately. To put the results in a broader perspective, we present the firstorder corrected dynamics of fluid branes carrying higherform charge by obtaining the general form of their equations of motion to poledipole order in the absence of external forces. To monopole order, we characterize the corresponding effective theory of viscous fluid branes by writing down the general form of the firstorder dissipative corrections in terms of the shear and bulk viscosities as well as the transport coefficient associated with charge diffusion. To dipole order, we furthermore, applying linear response theory, characterize the corresponding effective theory of stationary bent charged (an)isotropic fluid branes in terms of two sets of response coefficients, the Young modulus and the piezoelectric moduli.
We subsequently consider a large class of examples in gravity of this effective theory. In particular, we consider dilatonic black pbranes in two different settings: charged under a Maxwell gauge field and charged under a (p+1)form gauge field, including the Dbranes and Mbranes of type II string theory and M theory, respectively. Using familiar techniques, we compute the associated transport coefficients and uncover how the shear and bulk viscosities are modified in the presence of electric charge and a dilaton coupling. For the case of Maxwell black branes we furthermore compute the charge diffusion constant. We find that the shear viscosity to entropy bound is saturated and comment on proposed bounds for the bulk viscosity to entropy ratio. With the transport coefficients we compute the firstorder dispersion relations of the effective fluid and analyze the dynamical stability of the black branes.
We then focus on constructing stationary strained charged black brane solutions to first order in a derivative expansion. Using solution generating techniques and the bent neutral black brane as a seed solution, we obtain a class of charged black brane geometries carrying smeared Maxwell charge in EinsteinMaxwelldilaton theory. In the specific case of tendimensional spacetime we furthermore use Tduality to generate bent black branes with higherform charge, including smeared Dbranes of type II string theory. We compute the bending moment and the electric dipole moment which these solutions acquire due to the strain and uncover that their form is captured by classical electroelasticity theory. In particular, we find that the Young modulus and the piezoelectric moduli of the strained charged black brane solutions are parameterized by a total of four response coefficients, both for the isotropic as well as for the anisotropic cases.
Details
Date: Thursday 3 Oct
Time: 14:00
Place: Aud. A
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× 
MSc defense
Aud. A, Friday 4 Oct at 13:00
Therkel A. Zøllner Olesen
Twisted mass Wilson chiral perturbation theoryMSc defense
Therkel A. Zøllner Olesen
Twisted mass Wilson chiral perturbation theory
Abstract:
Details
Date: Friday 4 Oct
Time: 13:00
Place: Aud. A
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× 
HET journal club lunch
Fb6, Wednesday 9 Oct at 12:30
HET journal club lunch
Abstract:
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Date: Wednesday 9 Oct
Time: 12:30
Place: Fb6
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× 
Joint DISCOVERYHET Seminar
Aud. A, Thursday 10 Oct at 14:15
Alessandro Codello
Fluctuating (Fluid) MembranesJoint DISCOVERYHET Seminar
Alessandro Codello
Fluctuating (Fluid) Membranes
Abstract:
Fluid membranes are ddimensional reparametrization invariant hypersurfaces embedded in a Ddimensional target space. When d=2 and D=3, they are used as a model for real physical systems in biophysics and in softcondensed matter. Recently, they have been used to model generalized Galileon theories; in this case D=d+1.
After introducing functional Renormalization Group methods, I'll show how these can be applied to fluctuating membranes to obtain their phase diagram for general values of d and D.
Finally I'll propose a possible connection between fluctuating membranes (where both extrinsic and intrinsic curvatures are present) and quantum gravity (where only intrinsic curvature is present).
Details
Date: Thursday 10 Oct
Time: 14:15
Place: Aud. A
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× 
NBIA Colloquium
Aud A, Friday 11 Oct at 14:30
Jan Heinemeier
How accelerators, carbon14 and stable isotopes reveal news of past and present: Age of archaeological materials, tissue and wineNBIA Colloquium
Jan Heinemeier
How accelerators, carbon14 and stable isotopes reveal news of past and present: Age of archaeological materials, tissue and wine
Abstract:
I will give an overview of how levels of carbon 14 measured by
Accelerator Mass Spectrometry and stable isotopes can answer a wide
range of questions, such as:
How old are archaeological findings?
What did the Vikings eat?
How fast is turnover of human tissue?
Is your expensive Barolo wine actually from 1998?
Details
Date: Friday 11 Oct
Time: 14:30
Place: Aud A
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× 
HET journal club seminar
Fb6, Wednesday 23 Oct at 13:15
Thomas Vanel (LPTHE)
Dressing the electron star in a holographic superconductorHET journal club seminar
Thomas Vanel
Dressing the electron star in a holographic superconductor
Abstract:
Over the last five years, the gauge/gravity correspondence has been applied to describe quantum critical systems at finite density. The simplest model to consider is EinsteinMaxwell gravity, and the ground state of the system is described by ReissnerNordstrom black hole where all the charge is carried by the black hole. However, it turns out that this solution is unstable to the formation of both fermionic and bosonic matter, corresponding in the dual field theory to the creation of a Fermi surface and the onset of superconductivity, respectively. We consider EinsteinMaxwell system coupled to a perfect fluid of charged fermions and a charged scalar field. In addition to the black hole, electron star and holographic superconductor solutions, we find new asymptotically AdS4 solutions, dual to 2+1 CFTs at zero temperature and finite chemical potential, which contain both scalar hair and an electron star. We compute the free energy and show that these new solutions are thermodynamically favoured when they exist. Moreover, we find evidence for a continuous phase transition between the holographic superconductor and the new solutions.
Details
Date: Wednesday 23 Oct
Time: 13:15
Place: Fb6
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× 
Niels Bohr Lecture
Aud 3 @ HCØ, Wednesday 23 Oct at 15:15
Achim Rosch (Universität zu Köln)
Magnetic whirls in chiral magnets: skyrmions and monopolesNiels Bohr Lecture
Achim Rosch
Magnetic whirls in chiral magnets: skyrmions and monopoles
Abstract:
In chiral magnets and small magnetic fields lattices of magnetic whirls, socalled skyrmions, can be stabilized. These skyrmions can be manipulated by electric currents which are 56 orders of magnitude smaller than conventionally needed for the manipulation of magnetic structures. The very efficient coupling of the magnetic structure to currents is governed by Berry phases, which can be described by effective "emergent" electromagnetic fields. The topological quantization of the the skyrmions thereby leads to a quantization of the emergent magnetic flux. A change of topology has to occur by singular magnetic configurations [3] which act as sources and sinks of the emergent magnetic flux. Thereby they can be viewed as emergent magnetic monopols.
More info: http://www.nbi.ku.dk/Besoeg_os/niels_bohr_lectures/2013/achim_rosch/
Details
Date: Wednesday 23 Oct
Time: 15:15
Place: Aud 3 @ HCØ
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× 
Joint DiscoveryHET Seminar
Aud A, Thursday 24 Oct at 14:15
Jacopo Ghiglieri (McGill)
Higherorder calculations of hard probes in the quarkgluon plasmaJoint DiscoveryHET Seminar
Jacopo Ghiglieri
Higherorder calculations of hard probes in the quarkgluon plasma
Abstract:
At sufficiently high temperatures and vanishing chemical potential QCD exhibits a crossover to a deconfined phase, the quarkgluon plasma, which is probed in heavyion collision experiments. Hard probes, i.e. highly energetic, offequilibrium particles (photons, dileptons, jets), are of particular relevance in this investigation. In my talk I will discuss in detail the calculation of the thermal photon rate, which has recently been completed to nexttoleading order. I will show how Euclidean and sum rule techniques can be introduced and how this advancement renders the calculation simpler than expected. Finally, I will show how similar techniques can be applied to deal with highly energetic partons and jets.
Details
Date: Thursday 24 Oct
Time: 14:15
Place: Aud A
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× 
Joint DISCOVERYHET Seminar
Aud. A, Tuesday 29 Oct at 14:15
Subodh Patil (CERN)
Correlating features in the primordial specta, or, how do we know it really was an inflaton?Joint DISCOVERYHET Seminar
Subodh Patil
Correlating features in the primordial specta, or, how do we know it really was an inflaton?
Abstract:
CMB and matter density field observations derive from npoint correlation functions of the comoving curvature perturbation R. As far as we can tell, all observations to date are consistent with the predictions of the simplest models of singlefield slow roll inflation. However, if all we have access to are observations of correlators of adiabatic perturbations, one infers limited information as to what the background was actually doing. Degeneracies and dualities are known to exist between differing backgrounds that result in the same 2point correlators, which begs a host of operational questions: how do we know whether or not inflation really happened? What is the true nature of the inflaton? How does it embed itself in a sector that also contains the standard model?
In this talk I will review how the purported common lore `smoking gun' signatures of inflation are anything but, and demonstrate that one possible way to infer that inflation really happened would be to observe a hierarchy of correlations between the different npoint correlators of R. These correlations are a direct consequence of the effective field theory expansion of R, which nonlinearly realizes the breaking of time translational invariance by slow roll. The observation of such correlations in the npoint spectra over a range of efolds would directly confirm the nature of inflaton as an effectively single light scalar degree of freedom embedded in a theory that is UV completable, and is the consequence of transient stronger couplings of certain operators in the effective theory as inflation progresses. We discuss the prospects for observing such correlations in future LSS and 21cm observations.
Details
Date: Tuesday 29 Oct
Time: 14:15
Place: Aud. A
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× 
HET journal club lunch
Fb6, Wednesday 30 Oct at 12:30
HET journal club lunch
Abstract:
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Date: Wednesday 30 Oct
Time: 12:30
Place: Fb6
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× 
Joint DISCOVERYHET Seminar
Aud. A, Thursday 31 Oct at 14:15
Jacob Sonnenschein (Tel Aviv University)
Holographic Stringy HadronsJoint DISCOVERYHET Seminar
Jacob Sonnenschein
Holographic Stringy Hadrons
Abstract:
I will briefly review the stringy holographic calculation of Wilson lines and the sufficient conditions for confining ones. I will show that these are also the conditions to have a Reggelike holographic stringy mesons. I will show that classically the latter can be mapped into rotating strings in flat spacetime with massive endpoints. I will determine the massive modification of the Classical Regge trajectories. The issues associated with the quantization of such strings will be briefly reviewed. I will present fits of the modified trajectories to the experimental data of mesons starting from $\rho$ and $w$ mesons and all the way to $b\bar b$ mesons. The best fit values of the string tension, the intercept and the string endpoint masses will be presented. I will present the computation of the decay width of the holographic stringy mesons and their relation to the CNN and Lund models. I will describe the holographic stringy baryons including the location of the baryonic vertex and possible structures of such baryons. The stability of Y shape baryons will be discussed. Fits of holographic Regge trajectories to Nucleons and other baryons will be described. I will present arguments in favor of the picture of a single string with quark on one hand and a baryonic vertex and a diquark in the other hand.
Details
Date: Thursday 31 Oct
Time: 14:15
Place: Aud. A
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×  November 2013

NBIA Colloquium
Aud A, Friday 1 Nov at 14:15
Roger Penrose (University of Oxford)
Twistor Theory and Basic Physics: Some Recent New IdeasNBIA Colloquium
Roger Penrose
Twistor Theory and Basic Physics: Some Recent New Ideas
Abstract:
Twistor theory was initiated in 1963 as an alternative description of
spacetime physics, based fundamentally on the complex number system,
and dependent on crucial links with the formalism of quantum theory.
Despite many developments, little attention was paid to it until 40
years later, when Edward Witten pointed out significant connections with
the calculation of highenergy scattering processes. Important later
work by many researchers, including Andrew Hodges and Nima ArkaniHamed
have developed the theory in novel directions, all this leading to vast
simplifications in the calculation of scattering amplitudes. Much of
this activity is in the direction of perturbation analysis, early work
on exact solutions of the nonlinear Einstein and Yang–Mills equations
having been hampered by being restricted to just one helicity by the
socalled “googly problem”. A novel approach to circumventing this
difficulty will be presented.
Details
Date: Friday 1 Nov
Time: 14:15
Place: Aud A
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× 
DiscoveryHET Seminar
Aud A, Tuesday 5 Nov at 14:15
Chad Finley
Evidence for High Energy Astrophysical Neutrinos Seen by IceCubeDiscoveryHET Seminar
Chad Finley
Evidence for High Energy Astrophysical Neutrinos Seen by IceCube
Abstract:
The IceCube Neutrino Observatory, built deep within the glacial ice at the South Pole, Antarctica, became fully operational in 2011. This unique instrument allows the study of a wide range of phenomena, from dark matter searches to neutrino oscillations to cosmic ray physics. Analyses using the first year of data from the completed detector have revealed strong evidence of high energy neutrinos reaching Earth from distant space. Among these are the two highest energy neutrinos ever observed. Making a definitive measurement of this extraterrestrial flux will be a major advance toward the centuryold goal of identifying and studying the origins of high energy cosmic rays. In this talk, I will review recent highlights, and discuss the latest results and their analysis, which have also turned conventional thinking about neutrino telescopes upside down.
Details
Date: Tuesday 5 Nov
Time: 14:15
Place: Aud A
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HET journal club lunch
Fb6, Wednesday 6 Nov at 12:30
HET journal club lunch
Abstract:
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Date: Wednesday 6 Nov
Time: 12:30
Place: Fb6
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× 
HET journal club seminar
Fb6, Wednesday 13 Nov at 13:15
Yegor Korovin (University of Amsterdam)
On the field theory dual to Lifshitz spaceHET journal club seminar
Yegor Korovin
On the field theory dual to Lifshitz space
Abstract:
We consider holography for Lifshitz spacetimes with dynamical exponent z=1+epsilon^2, where epsilon is small. ?he holographically dual field theory is a specific deformation of the relativistic CFT, corresponding to the z=1 theory. We set up the holographic dictionary for EinsteinProca models and explain how renormalization turns the relativistic conformal invariance into nonrelativistic Lifshitz invariance with dynamical exponent z=1+epsilon^2. Using only QFT arguments we show that a particular class of deformations of CFTs generically leads to Lifshitz scaling invariance and we provide examples of such deformations. An analytic Lifshitz black brane up to second order in e is constructed. Relation to some topdown construction will be discussed. Based on 1304.7776 and 1306.3344.
Details
Date: Wednesday 13 Nov
Time: 13:15
Place: Fb6
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× 
DiscoveryHET Seminar
Aud M, Thursday 14 Nov at 14:15
Noboru Kawamoto (Hokkaido University)
Current Status of Exact Supersymmetry on the LatticeDiscoveryHET Seminar
Noboru Kawamoto
Current Status of Exact Supersymmetry on the Lattice
Abstract:
I will explain the fundamental difficulties of lattice
supersymmetry in an introductory way and then review
two of our proposals to solve these difficulties.
I will mainly focus on the basic ideas of the formulations.
Details
Date: Thursday 14 Nov
Time: 14:15
Place: Aud M
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× 
DiscoveryHET Seminar
Aud A, Tuesday 19 Nov at 14:15
Matti Jarvinen
Holographic models for QCD in the Veneziano limitDiscoveryHET Seminar
Matti Jarvinen
Holographic models for QCD in the Veneziano limit
Abstract:
I discuss holographic bottomup models for QCD in the Veneziano limit
(large N_f and N_c with fixed x=N_f/N_c). I will start by giving and
introduction to the topic and by reviewing earlier work. Then I will go
on discussing a specific class of models, named VQCD. The models are
constructed by putting together holographic models of YangMills theory
(improved holographic QCD) with Sentype tachyon actions inspired by
brane constructions, and by considering full backreaction. The resulting
phase diagrams and mass spectra meet expectations from QCD at
qualitative level.
Details
Date: Tuesday 19 Nov
Time: 14:15
Place: Aud A
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× 
HET journal club lunch
Fb6, Wednesday 20 Nov at 12:30
HET journal club lunch
Abstract:
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Date: Wednesday 20 Nov
Time: 12:30
Place: Fb6
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× 
Joint DiscoveryHET Seminar
Aud A, Thursday 21 Nov at 14:15
Ciaran Williams (NBIA & Discovery Center)
Bounding the Higgs width at the LHCJoint DiscoveryHET Seminar
Ciaran Williams
Bounding the Higgs width at the LHC
Abstract:
I will discuss the potential for the LHC to constrain the Higgs width.
At the LHC direct measurement of the width is impossible for
widths smaller than the detector resolution (of around 1 GeV).
Therefore an alternate approach is employed in which the
width is constrained from offshell H=>ZZ events. I will
present an overview of the method, including the analytic calculation
of gg=>ZZ using Ddimensional unitarity. I will then discuss
the potential improvements on the limits if Matrix Element
Methods are employed in the analysis.
Details
Date: Thursday 21 Nov
Time: 14:15
Place: Aud A
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× 
HET journal club seminar
Fb6, Wednesday 27 Nov at 13:15
Shahar Hadar (Hebrew University)
An action for reaction: an effective field theory study of postNewtonian radiative effectsHET journal club seminar
Shahar Hadar
An action for reaction: an effective field theory study of postNewtonian radiative effects
Abstract:
We present an effective field theory (EFT) describing radiation and radiationreaction effects in the postNewtonian approximation of General Relativity. Our formulation allows a unified treatment of outgoing radiation and its reaction force within an action formalism, and significantly economizes extant derivations. New results on radiation and reaction in general spacetime dimensions, obtained within our EFT, will be presented. In particular, the difference between even and odd spacetime dimensions in our context will be discussed. Finally, we will comment on the availability of a similar EFT treatment for nearextremal black holes.
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Date: Wednesday 27 Nov
Time: 13:15
Place: Fb6
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DiscoveryHET Seminar
Aud. A, Thursday 28 Nov at 14:15
Rutger Boels
Constructing the string Smatrix in target spaceDiscoveryHET Seminar
Rutger Boels
Constructing the string Smatrix in target space
Abstract:
String theory is a theory of strings amongst many other things. The usual way of describing string theory is therefore through its worldsheet. This however always involves an enormous amount of, in principle, redundant information. A simple question is: can string theory be defined without this redundancy? Based on joint, verysoontoappear work with Tobias Hansen I'll show a working definition of tree level string theory in a flat target space. We have a smallish set of conditions in target space whose unique solution is argued to be the usual string Smatrix. Interestingly, the notions of critical dimension and intercept are shown to arise naturally by requiring locality and unitarity. I'll end with more questions than answers, but at least the questions are interesting and wellposed. In particular there seem to be no fundamental restrictions to generalize to curved spaces.
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Date: Thursday 28 Nov
Time: 14:15
Place: Aud. A
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×  December 2013

HET journal club seminar
Bk2, Tuesday 3 Dec at 11:30
Niall Macpherson (Swansea)
Nonabelian Tduality and HolographyHET journal club seminar
Niall Macpherson
Nonabelian Tduality and Holography
Abstract:
My talk will be based on recent developements in nonabelian Tduality as a solution generating technique with applications to holography. I will start with a pedagogical review of Tduality along SU(2) isometries and then narrow my focus to dualising typeII SuGra solutions dual to QFTS with minimal SUSY. I will give several explicit examples where I will probe gauge theory dynamics, some inherited from the original solution some from the large number of fluxes typically generated by the duality. Along the way I will introduce generalised geometry into the narrative as this gives an elegant classification of the Tdual geometries in terms of gstructures and enables an extension of the duality to include calibrated sources, with clear applications to holography with smeared flavours. In addition one can show, quite generally, that in 6d the duality maps SU(3) to SU(2). The dual structure is actually dynamical SU(2) whenever the original solution is confining.
Details
Date: Tuesday 3 Dec
Time: 11:30
Place: Bk2
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HET journal club lunch
Fb6, Wednesday 4 Dec at 12:30
HET journal club lunch
Abstract:
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Date: Wednesday 4 Dec
Time: 12:30
Place: Fb6
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HET journal club seminar
Fb6, Wednesday 11 Dec at 11:15
Oluf Tang Engelund (Penn State)
Generalized Unitarity for 2D Integrable ModelsHET journal club seminar
Oluf Tang Engelund
Generalized Unitarity for 2D Integrable Models
Abstract:
Generalized unitarity is a powerful method for doing perturbative calculations. I will discuss how to apply it to worldsheet Smatrices for the Green Schwarz string in curved space. The studied theories are believed to be integrable to all orders in perturbation theory and symmetries have been used to determine exact Smatrices up to an overall dressing phase. Generalized unitarity can provide a simple way to check the proposed Smatrices perturbatively and to find dressing phases. I will give some 1 and 2loop examples and touch upon some of the potential challenges that may arise at higher loop orders.
Details
Date: Wednesday 11 Dec
Time: 11:15
Place: Fb6
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DiscoveryHET Seminar
Aud A, Wednesday 11 Dec at 14:15
Christoph Englert (University of Glasgow)
The Higgs Sector QuestDiscoveryHET Seminar
Christoph Englert
The Higgs Sector Quest
Abstract:
After the discovery of the Higgs boson in 2012, the importance of
reaching a better understanding of the nature of the electroweak scale
has become more important and more central to Particle Physics than
ever. I will discuss examples of how to improve and complement current
measurement strategies through exploiting new analysis techniques and
BSM interference effects in SM processes. The described programme not
only provides an opportunity to phenomenologically gain insights into
the mechanism of electroweak symmetry breaking itself, but also allows
to establish a "nohide" theorem for natural extensions of the SM.
Details
Date: Wednesday 11 Dec
Time: 14:15
Place: Aud A
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HET journal club lunch
Fb6, Wednesday 18 Dec at 12:30
HET journal club lunch
Abstract:
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Date: Wednesday 18 Dec
Time: 12:30
Place: Fb6
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