Experimental Investigation of Drain Noise in High Electron Mobility Transistors: Thermal and Hot Electron Noise

Posted by klaurent Caltech

Kavli Affiliate: Austin Minnich | Summary:We report the on-wafer characterization of $S$-parameters and microwave noise temperature ($T_50$) of discrete metamorphic InGaAs high electron mobility transistors (mHEMTs) at 40 K and 300 K and over a range of drain-source voltages ($V_DS$). From these data, we extract a small-signal model and the drain (output) noise current power […]


Continue.. Experimental Investigation of Drain Noise in High Electron Mobility Transistors: Thermal and Hot Electron Noise

Symphony: Cosmological Zoom-in Simulation Suites over Four Decades of Host Halo Mass

Posted by klaurent Stanford

Kavli Affiliate: Risa H. Wechsler | First 5 Authors: Ethan O. Nadler, Philip Mansfield, Yunchong Wang, Xiaolong Du, Susmita Adhikari | Summary: We present Symphony, a compilation of $262$ cosmological, cold dark matter-only zoom-in simulations spanning four decades of host halo mass, from $10^{11}~M_{mathrm{odot}}$ to $10^{15}~M_{mathrm{odot}}$. This compilation includes three existing simulation suites at the […]


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Finite-Time Error Bounds for Greedy-GQ

Posted by dbos UCAS

Kavli Affiliate: Yi Zhou | First 5 Authors: Yue Wang, Yi Zhou, Shaofeng Zou, , | Summary: Greedy-GQ with linear function approximation, originally proposed in cite{maei2010toward}, is a value-based off-policy algorithm for optimal control in reinforcement learning, and it has a non-linear two timescale structure with the non-convex objective function. This paper develops its tightest […]


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Finite-Time Error Bounds for Greedy-GQ

Posted by klaurent UCAS

Kavli Affiliate: Yi Zhou | First 5 Authors: Yue Wang, Yi Zhou, Shaofeng Zou, , | Summary: Greedy-GQ with linear function approximation, originally proposed in cite{maei2010toward}, is a value-based off-policy algorithm for optimal control in reinforcement learning, and it has a non-linear two timescale structure with a non-convex objective function. This paper develops its finite-time […]


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The X-ray polarimetry view of the accreting pulsar Cen X-3

Posted by klaurent MIT

Kavli Affiliate: Herman L. Marshall | First 5 Authors: Sergey S. Tsygankov, Victor Doroshenko, Juri Poutanen, Jeremy Heyl, Alexander A. Mushtukov | Summary: Cen X-3 is the first X-ray pulsar discovered 50 years ago. Radiation from such objects is expected to be highly polarized due to birefringence of plasma and vacuum associated with propagation of […]


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PROBs and perverse sheaves II. Ran spaces and 0-cycles with coefficients

Posted by klaurent Tokyo

Kavli Affiliate: Mikhail Kapranov | Summary:We consider the space Z(C,L) of 0-cycles on the complex line C with coefficients in a commutative monoid L subject to certain conditions. Such spaces include the symmetric products (for L=Z_+) and the Ran space (for L=T= True, False being the Boolean algebra of truth values). We describe the appropriately […]


Continue.. PROBs and perverse sheaves II. Ran spaces and 0-cycles with coefficients

PROBs and perverse sheaves II. Ran spaces and 0-cycles with coefficients

Posted by klaurent Tokyo

Kavli Affiliate: Mikhail Kapranov | First 5 Authors: Mikhail Kapranov, Vadim Schechtman, , , | Summary: We consider the space Z(C,L) of 0-cycles on the complex line C with coefficients in a commutative monoid L subject to certain conditions. Such spaces include the symmetric products (for L=Z_+) and the Ran space (for L=T={ True, False} […]


Continue.. PROBs and perverse sheaves II. Ran spaces and 0-cycles with coefficients

Static spherical vacuum solutions in the bumblebee gravity model

Posted by klaurent Peking

Kavli Affiliate: Lijing Shao | First 5 Authors: Rui Xu, Dicong Liang, Lijing Shao, , | Summary: The bumblebee gravity model is a vector-tensor theory of gravitation where the vector field nonminimally couples to the Ricci tensor. By investigating the vacuum field equations with spherical symmetry, we find two families of black-hole (BH) solutions in […]


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Discovery of an Ultra Lithium-rich Metal-Poor Red Giant star

Posted by klaurent MIT

Kavli Affiliate: Anna Frebel | First 5 Authors: Jeremy Kowkabany, Rana Ezzeddine, Corinne Charbonnel, Ian U. Roederer, Yangyang Li | Summary: We present the discovery of 2MASS J05241392-0336543 (hereafter J0524-0336), a very metal-poor ([Fe/H]=-2.43 pm 0.16), highly r-process-enhanced ([Eu/Fe]=+1.34 pm 0.10) Milky Way halo field red giant star, with an ultra high Li abundance of […]


Continue.. Discovery of an Ultra Lithium-rich Metal-Poor Red Giant star