A possible sequential star formation in the giant molecular cloud G174+2.5

We investigate the nature of 14 embedded clusters (ECs) related to a group of four H II regions Sh2-235, Sh2-233, Sh2-232, and Sh2-231 in the giant molecular cloud G174 + 2.5. Projected towards the Galactic anticentre, these objects are a possible example of the collect and collapse scenario. We derive astrophysical parameters (age, reddening, distance, core and cluster radii) for the ECs and investigate the relationship among their parameters. Parameters are derived with field decontaminated 2MASS colour-magnitude diagrams (CMDs) and stellar radial density profiles (RDPs). The CMDs of these young clusters are characterised by a poorly-populated main sequence and a significant number of pre-main sequence stars, affected by differential reddening. The ECs are KKC 11, FSR 784, Sh2-235 E2, Sh2-235 Cluster, Sh2-233SE Cluster, BDSB 73, Sh2-235B Cluster, BDSB 72, BDSB 71, Sh2-232 IR, PCS 2, and the newly found clusters CBB 1 and CBB 2. We were able to derive fundamental parameters for all ECs in the sample. Structural parameters are derived for FSR 784, Sh2-235 Cluster and Sh2-235E2.Comment: 14 pages and 15 figures; MNRAS 201

Vevacious: A Tool For Finding The Global Minima Of One-Loop Effective Potentials With Many Scalars

Several extensions of the Standard Model of particle physics contain additional scalars implying a more complex scalar potential compared to that of the Standard Model. In general these potentials allow for charge and/or color breaking minima besides the desired one with correctly broken SU(2)_L times U(1)_Y . Even if one assumes that a metastable local minimum is realized, one has to ensure that its lifetime exceeds that of our universe. We introduce a new program called Vevacious which takes a generic expression for a one-loop effective potential energy function and finds all the tree-level extrema, which are then used as the starting points for gradient-based minimization of the one-loop effective potential. The tunneling time from a given input vacuum to the deepest minimum, if different from the input vacuum, can be calculated. The parameter points are given as files in the SLHA format (though is not restricted to supersymmetric models), and new model files can be easily generated automatically by the Mathematica package SARAH. This code uses HOM4PS2 to find all the minima of the tree-level potential, PyMinuit to follow gradients to the minima of the one-loop potential, and CosmoTransitions to calculate tunneling times.Comment: 44 pages, 1 figure, manual for publicly available software, v2 corresponds to version accepted for publication in EPJC [clearer explanation of scale dependence and region of validity, explicit mention that SLHA files should have blocks matching those expected by model files, updated references

Design of a Broadband Amplifier for High Speed Applications

This paper provides comprehensive insight into the design approach followed for an amplifier dedicated to high speed base band signals. To demonstrate the methodology, an amplifier consisting of nine PHEMT cascode cells within a distributed amplifier topology was designed. The resulting frequency response is 40 GHz at the 3-dB point, and the output voltage for a 43 Gbps eye diagram is 7.3 Vpp at the chip terminal

Weyl geometry, anti-De Sitter space, and Φ4\Phi^4-theory

We study the Gaussian approximation to the quantum fluctuations of the metric of the four dimensional anti-De Sitter spacetime. The associated massless scalar field has a quartic self interaction, for which we construct the generating functional of the $n$-point correlation functions. The concomitant infrared divergence is cured by a mass renormalization provided by the cosmological constant, which is also responsible for the renormalization of the coupling constant of the field theory.Comment: 9 pages, 1 figur