11 DEC 2019
13:30 - 15:00

We show how in a matrix inflationary model in which there is a non-minimal coupling between the matrix inflatons and gravity --hence dubbed Non-M-flation-- some of the disadvantages of the minimal model can be avoided. In particular, the number of D3 branes can be reduced substantially to $\lesssim \mathcal{O}(100)$, which can alleviate the "potential" backreaction problem of large number of D3 branes on the background geometry. This is achieved by values of non-minimal coupling of order few hundred, which is much smaller than that of Higgs Inflation. The prediction of the model in the symmetry breaking part of the potential, which is a local attractor and can support eternal inflation, is compatible with the latest PLANCK results. In contrast to the minimal model, the spectator fields can partially or completely reheat the universe, depending on the symmetry-breaking vacuum expectation value and the non-minimal coupling parameter. We also comment on how the presence of gauge species keep the UV cutoff at around the Planck scale in the Einstein frame and, in contrast to the Higgs inflation, the problem of field displacements beyond the cutoff does not occur.

11 DEC 2019
14:00 - 16:00

Venue:
School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM),
Opposite the ARAJ, Artesh Highway, Tehran, Iran on map




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Send an empty email to: scs at ipm dot ir on the subject of: #join

11 DEC 2019
15:00 - 16:00

Abstract: we examine the dimension-six operators contributing to top quark pair production associated with neutrino pair at the LHC. Potential constraints on both CP-even and CP-odd dimension-six operators involving gauge bosons, Higgs boson, and top quark are determined by considering two opposite-sign charged leptons, missing energy, and two b-tagged jets in the final state. The analysis is performed for a High Luminosity scenario of the LHC with an integrated luminosity of 3 ab^−1 of proton-proton collisions at the center-of-mass energy of 14 TeV. The 95% confidence intervals are computed on the contributing dimension-six operators using a realistic detector simulation of the upgraded CMS detector considering an average of 200 proton-proton interactions per bunch crossing. We also obtain an improvement in the bounds on the dimension-six operators coefficients by combining this channel and ttZ¯ channel, where Z → l+l−. It is found that the combination would improve the constraints on some coefficients by two order of magnitudes and extend the sensitivity down to 10^-5


Larak Seminar Room

11 DEC 2019
16:00 - 00:00

Conference Hall, Farmanieh, Bldg (1st floor), IPM

12 DEC 2019
-

Farmanieh Conference Hall

12 DEC 2019
11:00 - 12:00

Abstract: In this series of talks, I present a generalization of the Bantilan-Ishi-Romatschke (BIR) solution of relativistic hydrodynamics (RH) to relativistic magnetohydrodynamics (RMHD). I start by introducing the symmetry arguments used to solve the equations of RH on the boundary of a Kerr-AdS5 black hole. Using conformal hydrodynamics I reproduce the BIR solution from the aforementioned results. Since the dual black hole is rotating, the transformed solution resembles a non-central collision. Using the symmetries of the boundary of the Kerr-AdS5 black hole, and certain simplifying assumptions I solve the equations of RMHD on this boundary for a highly conductive fluid. As in the RH case, I transform the resulting solution to the flat spacetime. Furthermore, I show that the force-free condition causes the magnetic field to become singular at particular points and propose a regularization process for removing the singularities. The regularization process reveals the importance of non-vanishing electrical current in RMHD.


Larak Seminar Room

14 DEC 2019
14:00 - 16:00

Venue:
School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM),
Opposite the ARAJ, Artesh Highway, Tehran, Iran on map




* To join the mailing list:
Send an empty email to: scs at ipm dot ir on the subject of: #join

19 DEC 2019
10:00 - 11:00

TBA

23 DEC 2019
14:00 - 15:00

Some historical stock or option-implied volatilities do not incorporate a complete view of the forward volatility. In these circumstances, the volatility of future prices can not be presented by a single number or a predetrmined function of the time and price or even a stochastic process with given statistics. So under ambiguity, future volatility value, based on observations of probability measures, is proposed to be lied in a bounded set. To specify the market more precisely, a family of probability measures as {Pθ : θ ∈ Θ} is indicated instead of fixing a probability measure. In such uncertain environment, non-uniqueness of martingale measures prevent pricing and perfectly replicating hedges with certainty. The first notation in the study of stochastic calculus under uncertainty is denoted by E? , which is called sublinear expectation. The nice operator E? provide a robust way for pricing risk positions in the uncertain economy and also define a coherent risk measure on acceptabe sets. Here, new triple (Ω,H ,E?) has the most important role in the stochastic calculus in the presence of uncertain probablities similar to (Ω,F,P) in the classical notation. In this talk, we intend to introduce the necessary tools for the problem of probability model under uncertainty with application to finance.