HIP NEWS December 16th 2013

HIP NEWS December 16th 2013
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HIP Staff News
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Matti Kortelainen has received the CMS Achievement and Special Recognition Awards 2013 for his work in performance tool development and studies in the areas of Reconstruction, HLT, and DQM since 2010.

http://cms.web.cern.ch/content/achievement-awards-2013
http://cms-mgt-fps-board.web.cern.ch/cms-mgt-fps-board/awardees.php#RECOGNITION_LIST

HIP congratulates Matti!

HIP Annual Report
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Please take note of the reporting instructions mailed on Dec. 3rd.

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 17 December 2013 at 10.15 in A315
Roshan Foadi (Helsinki)
See web.

HIP NEWS December 9th 2013

HIP NEWS December 9th 2013
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HIP STAFF MEETING (YT-MEETING)
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Time: Tuesday, December 10th, 2013 at 16:00.
Place: CERN, Geneva, Room 13-2-005.

Agenda:
1. Opening of the meeting
2. Election of the secretary of the meeting and two scrutinizers
of the minutes
3. Status report of the Institute
4. The project structure of the Institute in 2014
5. The budget of the Institute for 2014
6. Mobility compensation for 2014
7. Other matters brought up by the staff

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 10 December 2013 at 10.15 in A315
Juha Jäykkä (Nordita)
Isospinning hopfions

Abstract:
The problem of constructing internally rotating solitons of fixed angular frequency omega in the Faddeev-Skyrme model is reformulated as a variational problem for an energy-like functional, called pseudoenergy, which depends parametrically on omega. This problem is solved numerically using a gradient descent method, without imposing any spatial symmetries on the solitons, and the dependence of the solitons’ energy on omega, and on their conserved total isospin J. It is found that, generically, the shape of a soliton is independent of omega, and that its size grows monotonically with omega. A simple elastic rod model of time-dependent hopfions is developed which, despite having only one free parameter, accounts well for most of the numerical results.

VISITORS
———
S. Niyogi 15.9.-15.12 (KH)

HIP NEWS December 2nd 2013

HIP NEWS December 2nd 2013
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HIP STAFF MEETING (YT-MEETING)
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Time: Tuesday, December 10th, 2013 at 16:00.
Place: CERN, Geneva, Room 13-2-005.

Agenda:
1. Opening of the meeting
2. Election of the secretary of the meeting and two scrutinizers of the minutes
3. Status report of the Institute
4. The project structure of the Institute in 2014
5. The budget of the Institute for 2014
6. Mobility compensation for 2014
7. Other matters brought up by the staff

PARTICLE PHYSICS SEMINARS
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Venue: A315
Speaker: Stefano Di Chiara
Date: 02/12/2013(Monday)
Time: 14:15 hrs
Stefano will discuss the following paper on Monday (02/12/13).

http://arxiv.org/abs/1308.0295

With regards,
Priyotosh Bandyopadhyay

VISITORS
———
S. Niyogi 15.9.-15.12 (KH)
P. Prešnajder 18.11. – 2.12. (AT)

HIP NEWS November 25th 2013

HIP NEWS November 25th 2013
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DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 26 November 2013 at 10.15 in A315
Tommi Markkanen (Helsinki)
Applications of Curved Space Field Theory for Scalar Field Models of Inflation

Abstract:
Now in the wake of the Planck mission a demand for improving the predictions of standard
inflationary models has arisen. In this talk I will discuss the inclusion of quantum
corrections in the equations of motion for a scalar matter field present during inflation,
in the framework of curved space field theory. Among the key questions will be how to
perform proper renormalization at the equation of motion level, without referring to an
effective action. I will also present a quantum slow-roll calculation that incorporates the
important infrared effects of dynamical space-time and show how a re-summing of diagrams
cures a potential IR enhancement.

COSMO-Seminar
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Wednesday 27 November 2013 at 14.15 in A315
Jacques Wagstaff (Hamburg)
Amplification of magnetic fields from turbulence in the early Universe

Abstract:
We investigate the turbulent small-scale dynamo mechanism for the amplification of a seed magnetic
field in the radiation era. Velocity perturbations in the primordial plasma are sourced by density perturbations.
On small scales we argue that turbulence becomes fully developed since the Reynolds numbers are
very large and eddy-flows interact effectively. Hence, we demonstrate that the conditions are right for efficient
dynamo amplification leading to large magnetic fields on small scales. Such fields could leave an imprint in
the black-body spectrum of the CMB which might be measurable with forthcoming telescopes such as PIXIE.

VISITORS
———
S. Niyogi 15.9.-15.12 (KH)
P. Prešnajder 18.11. – 2.12. (AT)
J. Wagstaff 25.11. – 29.11. (SN)

HIP NEWS November 18th 2013

HIP NEWS November 18th 2013
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COSMO-Seminar
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Nov 20 (Wed), 14:15 in A315
Shuang-Yong Zhou (Trieste)
Gravitational waves from oscillon/Q-ball preheating

Abstract:
Oscillons are long-lived, localized excitations of nonlinear scalar fields which may be copiously produced during preheating after inflation, leading to a possible oscillon-dominated phase in the early Universe. For example, this can happen after axion monodromy inflation, on which we run our simulations. We investigate the stochastic gravitational wave background associated with an oscillon-dominated phase. An isolated oscillon is spherically symmetric and does not radiate gravitational waves, and we show that the flux of gravitational radiation generated between oscillons is also small. However, a significant stochastic gravitational wave background may be generated during preheating itself (i.e, when oscillons are forming), and in this case the characteristic size of the oscillons is imprinted on the gravitational wave power spectrum, which has multiple, distinct peaks.
If time allows, I will also briefly mentioned on-going work about interlocked Q-balls and their gravitational wave production.

VISITORS
———
R. Foadi 4.11. – 19.11. (KT)
S. Niyogi 15.9.-15.12 (KH)
P. Pandita 4.11. – 21.11. (KH)
P. Prešnajder 18.11. – 2.12. (AT)
O. Taanila, 18.11. – 22.11. (AV)
S.-Y. Zhou, 19.11. – 21.11. (SN)

HIP NEWS November 11th 2013

HIP NEWS November 11th 2013
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DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 12 November 2013 at 10.15 in A315
Antonio Racioppi (NICPB, Tallinn)
Towards Completing the Standard Model

Abstract: We study the standard model (SM) in its full perturbative validity range between LambdaQCD and the U(1)_Y Landau pole, assuming that a yet unknown gravitational theory in the UV does not introduce additional particle thresholds, as suggested by the tiny cosmological constant and the absence of new stabilizing physics at the EW scale. We find that, due to dimensional transmutation, the SM Higgs potential has a global minimum at 10^26 GeV, invalidating the SM as a phenomenologically acceptable model in this energy range. We show that extending the classically scale invariant SM with one complex singlet scalar S allows us to: (i) stabilize the SM Higgs potential; (ii) induce a scale in the singlet sector via dimensional transmutation that generates the negative SM Higgs mass term via the Higgs portal; (iii) provide a stable CP-odd singlet as the thermal relic dark matter due to CP-conservation of the scalar potential; (iv) provide a degree of freedom that can act as an inflaton in the form of the CP-even singlet. The logarithmic behavior of dimensional transmutation allows one to accommodate the large hierarchy between the electroweak scale and the Landau pole, while understanding the latter requires a new non-perturbative view on the SM.

COSMO-Seminar
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Nov 13 (Wed), 14:15 in A315
David Mulryne (Queen Mary)
Multiple field inflation: Methods and models

I will discuss inflation driven by more than one scalar field, which can be argued to be the generic situation. First I will review how the dynamics can change when more than one field is active during inflation, and then consider some popular two field models from the literature. I will discuss how simple techniques allow these models to be confronted by observations, and show how they are constrained by the recent Planck results. These simple techniques exploit the super-horizon ‘separate universe’ approximation to cosmological perturbation theory and are inadequate in many circumstances. Finally, therefore, I will discuss some recent work which aims to allow us to calculate all the observational signatures of multiple field models of inflation without recourse to these simplified methods.

VISITORS
———
R. Foadi 4.11. – 19.11. (KT)
D. Mulryne, 11.11. – 16.11. (SN)
S. Niyogi 15.9.-15.12 (KH)
P. Pandita 4.11. – 21.11. (KH)
A. Racioppi, 11.11. – 13.11. (KT)
C. Royon, 11.11. – 14.11. (FD)
F. Sannino, 12.11. – 14.11. (KT)
Y. Schröder, 15.11. (KK)

HIP NEWS November 4th 2013

HIP NEWS November 4th 2013
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UNIVERSITY OF HELSINKI ELECTIONS NOV. 4 – 5
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See, https://flamma.helsinki.fi/portal/home/sisalto?_nfpb=true&_pageLabel=pp_list&placeId=HY284743

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 5 November 2013 at 10.15 in A315
Alberto Ramos (Desy)
The gradient flow and the determination of alpha_s

Abstract:
Measuring the intensity of the strong force has his inherent problems due to the non-perturbative nature of the interaction. In this talk I will review one of the lattice approaches to the problem of how to measure the intensity of strongly coupled gauge theories and some of its most recent developments. These include the use of the gradient flow, a tool that allows an easy non-perturbative definition of the coupling constant, but with the potential of having other applications beyond the lattice.

VISITORS
———
R. Foadi 4.11. – 19.11. (KT)
A. Golovnev 24.10. – 6.11. (KE)
C. Kouvaris 30.10. – 4.11. (KT,AV)
S. Niyogi 15.9.-15.12 (KH)
P. Pandita 4.11. – 21.11. (KH)
A. Ramos 4.11. – 7.11. (KR)
G. Tasinato 5.11. – 7.11. (SN)

HIP NEWS October 28th 2013

HIP NEWS October 28th 2013
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DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 29 October 2013 at 10.15 in A315
Kimmo Tuominen (Helsinki)
Beyond the Standard Model

Abstract: The existence of the Higgs mechanism and the associated scalar particle has been firmly established by LHC experiments. While the Standard Model (SM) of elementary particle interactions provides an excellent parametrisation of LHC data, the need for physics beyond SM remains as serious as ever: for example the origin of the weak scale and fermion masses, the dark matter abundance and the matter-antimatter asymmetry remain unexplained. Aspects of these issues are discussed in this talk with concrete and testable model examples.

Thursday 31 October 2013 at 10.15 in A315
Chris Kouvaris (CP3, Odense)
The dark side of Stars

Abstract: I will talk about how compact stars such as white dwarfs and neutron stars can impose constraints on properties of dark matter models. Dark matter accumulation into neutron stars can change the thermal evolution of the star due to dark matter annihilation taking place inside the star. In the case of asymmetric dark matter, WIMP accumulation might lead under certain conditions to the formation of a black hole that can potentially destroy the star, thus imposing constraints on several models of dark matter.

COSMO-Seminar
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Oct 30 (Wed), 14:15 in A315
Alexey Golovnev (Saint-Petersburg)
ADM analysis of massive and bimetric gravity models and the problem of ghosts.

Abstract: We review the ADM analysis of massive gravity and bigravity models, with emphasis on avoidance of Boulware-Deser-ghost-like excitations. The models of dRGT type and a version of bimetric variational principle are discussed in detail. Multimetric models and vielbein formalism are also mentioned.

Fall 2013 PhD school, “Supersymmetry or not, what is the evidence?”
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A particle/astro PhD school, Copenhagen
on supersymmetry, October 28-November 1st

https://indico.nbi.ku.dk/conferenceDisplay.py?confId=590

VISITORS
———
A. Golovnev 24.10. – 6.11. (KE)
M. Hindmarsh 30.10.-1.11. (KR)
S. Huber 30.10.-1.11. (KR)
S. Niyogi 15.9.-15.12 (KH)

HIP NEWS October 21st 2013

HIP NEWS October 21st 2013
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HIP PERSONNEL LIST UPDATE
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Please check the information on the Personnel list in HIP web pages.

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 22 October 2013 at 10.15 in A315
Tomas Brauner (Helsinki)
Spontaneous symmetry breaking and Nambu-Goldstone bosons: some news in the old story

Abstract: The concept of spontaneous symmetry breaking is key to understanding of a vast range of physical phenomena such as superfluidity, ferromagnetism, or the origin of masses of elementary particles. I will provide a brief introduction to this classic topic and then review some recent results: (i) Completed classification and counting of Nambu-Goldstone bosons; (ii) A new class of states protected by symmetry: the massive Nambu-Goldstone bosons. I will conclude by outlining some yet unresolved problems, relevant for applications to a variety of quantum many-body systems.

Fall 2013 PhD school, “Supersymmetry or not, what is the evidence?”
——————————————————————–
A particle/astro PhD school, Copenhagen
on supersymmetry, October 28-November 1st

https://indico.nbi.ku.dk/conferenceDisplay.py?confId=590

VISITORS
———
A. Golovnev 24.10. – 6.11. (KE)
L. Laperashvili 1.10. – 22.10. (AT)
S. Niyogi 15.9.-15.12 (KH)

HIP NEWS October 14th 2013

HIP NEWS October 14th 2013
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The workplace wellbeing survey 1.10. – 15.10.2013
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The workplace wellbeing survey for universities is part of a cooperation agreement with Varma Mutual Pension Insurance Company that includes all Finnish universities.

The workplace wellbeing survey will be accessible Tuesday to Tuesday, 1-15 October 2013.

The survey can be taken at
https://my.surveypal.com/yliopistojen_tyohyvinvointikysely_2013_-_Helsingin_yliopisto

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 15 October 2013 at 10.15 in A315
Holger Bech Nielsen (Niels Bohr Institute)
What is so special about the Standard Model? Small representations.

Now it seems that the Standard Model gets more and more supported without yet convincing signs of new physics, so one may with increased strength ask: Why is just the a priori not so obvious Standard Model being selected by Nature? Don Bennett and I started by asking for a quantity depending on the gauge gruop which would be maximal on the Standard Model Group. We found a quantity which is essentially the ratio of the quadratic Casimir for the adjoint representation relative to the quadratic Casimir for the “smallest” faithful representation. Essentially the same maximization principle seems also to deliver the space-time dimension and the representation for the Higgs field. Taking into account the requirements of no anomalies, it is also very close at least to tell what Weyl field representations one shall find. So approximately the whole Standard Model except the number of families come out from such a really “small representation” principle!

Fall 2013 PhD school, “Supersymmetry or not, what is the evidence?”
——————————————————————–
A particle/astro PhD school, Copenhagen
on supersymmetry, October 28-November 1st

https://indico.nbi.ku.dk/conferenceDisplay.py?confId=590

 

VISITORS
———
A. Golovnev 24.10. – 6.11. (KE)
L. Laperashvili 1.10. – 22.10. (AT)
H.B. Nielsen 14.10. – 18.10. (AT)
S. Niyogi 15.9.-15.12 (KH)