On 3D Minimal Massive Gravity

We study linearized equations of motion of the newly proposed three dimensional gravity, known as minimal massive gravity, using its metric formulation. We observe that the resultant linearized equations are exactly the same as that of TMG by making use of a redefinition of the parameters of the model. In particular the model admits logarithmic modes at the critical points. We also study several vacuum solutions of the model, specially at a certain limit where the contribution of Chern-Simons term vanishes.Comment: 15 pages, no figures, typos fixed, journal versio

Fermions in non-relativistic AdS/CFT correspondence

We extend the non-relativistic AdS/CFT correspondence to the fermionic fields. In particular we study the two point function of a fermionic operator in non-relativistic CFTs by making use of a massive fermion propagating in geometries with Schrodinger group isometry. Although the boundary of the geometries with Schrodinger group isometry differ from that in AdS geometries where the dictionary of AdS/CFT is established, using the general procedure of AdS/CFT correspondence, we see that the resultant two point function has the expected form for fermionic operators in non-relativistic CFTs, though a non-trivial regularization may be needed.Comment: 12 pages,Latex file; V2: typos corrected, refs adde

On Complexity for Higher Derivative Gravities

Using "complexity=action" proposal we study complexity growth of certain gravitational theories containing higher derivative terms. These include critical gravity in diverse dimensions. One observes that the complexity growth for neutral black holes saturates the proposed bound when the results are written in terms of physical quantities of the model. We will also study effects of shock wave to the complexity growth where we find that the presence of massive spin-2 mode slows down the rate of growth.Comment: 18 pages, 3 figures, journal versio

Complexity Growth with Lifshitz Scaling and Hyperscaling Violation

Using complexity=action proposal we study the growth rate of holographic complexity for Lifshitz and hyperscaling violating geometries. We will consider both one and two sided black branes in an Einstein-Maxwell-Dilaton gravitational theory. We find that in either case Lloyd's bound is violated and the rate of growth of complexity saturates to a value which is greater than twice the mass of the corresponding black brane. This value reduces to the mass of the black brane in the isotropic case. We show that in two sided black brane the saturation happens from above while for one sided black brane it happens from below.Comment: 17 pages, 4 figures, v2: typos corrected, references added, v3: Minor corrections, New counter terms added that also contribute to the rate of complexity growth. The conclusion is not changed, now 19 pages, v4: matches published versio

Holographic renormalization of 3D minimal massive gravity

We study holographic renormalization of 3D minimal massive gravity using the Chern-Simons-like formulation of the model. We explicitly present Gibbons- Hawking term as well as all counterterms needed to make the action finite in terms of dreibein and spin-connection. This can be used to find correlation functions of stress tensor of holographic dual field theory.Comment: 26 pages, no figures, typos fixed, Ref. adde

Assessment of pH-responsive nanoparticles performance on laboratory column flotation cell applying a real ore feed

Nanoparticles (NPs) can promote the column flotation process in mining industry. Nanoparticles’ effects on column flotation process (copper recovery, grade and flotation rate constant) are assessed in Sarcheshmeh Copper Complex, Iran, through response surface methodology (RSM) optimization technique. The γ-Al2O3, α-Fe2O3, SiO2, and TiO2 nanoparticles are selected for these experiments. A flotation rate constant is chosen as a response to assess the effect of nanoparticles on flotation in its kinetic sense. The process pH and nanoparticle dosage are selected as the influential parameters. Results obtained from RSM indicated that the maximum percentage of Cu recovery and grade is obtained at pH of 12 and nanoparticle dosage of 6 kg/t, through α-Fe2O3 and γ-Al2O3 nanoparticles, respectively. Applying nanoparticles in particular γ-Al2O3 and α-Fe2O3 increases the Cu recovery by 8–10% together with the grade by 3–6% in a significant manner. It is revealed that nanoparticles could effectively be applied in enhancing the flotation performance