Moscow Institute of Physics and Technology

About: Moscow Institute of Physics and Technology is a education organization based out in Dolgoprudnyy, Russia. It is known for research contribution in the topics: Laser & Large Hadron Collider. The organization has 8594 authors who have published 16968 publications receiving 246551 citations. The organization is also known as: MIPT & Moscow Institute of Physics and Technology (State University).

Towards a proof of agt conjecture by methods of matrix models

Abstract: A matrix model approach to proof of the AGT relation is briefly reviewed. It starts from the substitution of conformal blocks by the Dotsenko–Fateev β-ensemble averages and Nekrasov functions by a double deformation of the exponentiated Seiberg–Witten prepotential in β≠1 and gs≠0 directions. Establishing the equality of these two quantities is a typical matrix model problem.

Direct numerical simulation of disturbances generated by periodic suction-blowing in a hypersonic boundary layer

Abstract: A numerical algorithm and code are developed and applied to direct numerical simulation (DNS) of unsteady two-dimensional flow fields relevant to stability of the hypersonic boundary layer. An implicit second-order finite-volume technique is used for solving the compressible Navier–Stokes equations. Numerical simulation of disturbances generated by a periodic suction-blowing on a flat plate is performed at free-stream Mach number 6. For small forcing amplitudes, the second-mode growth rates predicted by DNS agree well with the growth rates resulted from the linear stability theory (LST) including nonparallel effects. This shows that numerical method allows for simulation of unstable processes despite its dissipative features. Calculations at large forcing amplitudes illustrate nonlinear dynamics of the disturbance flow field. DNS predicts a nonlinear saturation of fundamental harmonic and rapid growth of higher harmonics. These results are consistent with the experimental data of Stetson and Kimmel obtained on a sharp cone at the free-stream Mach number 8.

Coupled-Channel Interpretation of the LHCb Double- J / ψ Spectrum and Hints of a New State Near the J / ψ J / ψ Threshold

Abstract: Recently, the LHCb Collaboration reported pronounced structures in the invariant mass spectrum of $J/\ensuremath{\psi}$ pairs produced in proton-proton collisions at the Large Hadron Collider. In this Letter, we argue that the data can be very well described within two variants of a coupled-channel approach employing $T$ matrices consistent with unitarity: (i) with just two channels, $J/\ensuremath{\psi}J/\ensuremath{\psi}$ and $\ensuremath{\psi}(2S)J/\ensuremath{\psi}$, as long as energy-dependent interactions in these channels are allowed, or (ii) with three channels $J/\ensuremath{\psi}J/\ensuremath{\psi}$, $\ensuremath{\psi}(2S)J/\ensuremath{\psi}$, and $\ensuremath{\psi}(3770)J/\ensuremath{\psi}$ with just constant contact interactions. Both formulations hint at the existence of a near-threshold state in the $J/\ensuremath{\psi}J/\ensuremath{\psi}$ system with the quantum numbers ${J}^{PC}={0}^{++}$ or ${2}^{++}$, which we refer to as $X(6200)$. We suggest experimental tests to check the existence of this state and discuss what additional channels need to be studied experimentally to allow for distinctive tests between the two mechanisms proposed. If the molecular nature of $X(6200)$, as hinted by the three-channel approach, is confirmed, many other double-quarkonium states should exist driven by the same binding mechanism. In particular, there should be an ${\ensuremath{\eta}}_{c}{\ensuremath{\eta}}_{c}$ molecule with a similar binding energy.

Actin polymerization downstream of integrins: signaling pathways and mechanotransduction

Abstract: A cell constantly adapts to its environment. Cell decisions to survive, to proliferate or to migrate are dictated not only by soluble growth factors, but also through the direct interaction of the cell with the surrounding extracellular matrix (ECM). Integrins and their connections to the actin cytoskeleton are crucial for monitoring cell attachment and the physical properties of the substratum. Cell adhesion dynamics are modulated in complex ways by the polymerization of branched and linear actin arrays, which in turn reinforce ECM-cytoskeleton connection. This review describes the major actin regulators, Ena/VASP proteins, formins and Arp2/3 complexes, in the context of signaling pathways downstream of integrins. We focus on the specific signaling pathways that transduce the rigidity of the substrate and which control durotaxis, i.e. directed migration of cells towards increased ECM rigidity. By doing so, we highlight several recent findings on mechanotransduction and put them into a broad integrative perspective that is the result of decades of intense research on the actin cytoskeleton and its regulation.