While reading up on anti-deSitter spaces in [1], I encountered the following quote attributed to Gauss by the author: “I have sometimes in jest expressed the wish that Euclidean geometry is not true. For then we would have an absolute a priori unit of measurement.” This is not just an empty wish. If quantum gravity… Continue reading Cosmological Curvature and the Planck Scale
The 23th DAE-BRNS High Energy Physics Symposium was held at IIT Madras from Dec 10 – Dec 14. It was an interesting event. I met lots of very smart people. My abstract based on my paper [1] had been selected for a talk in the “Formal Theory” parallel session on Dec 11. Interestingly the talk… Continue reading DAE-HEP 2018 – Preons, Fermions and All That
There are two nice reference management apps out there with desktop and web versions: Mendeley and Zotero. Zotero is apparently the original open source version from which the developers of Mendeley decided to develop a more commercial version, which was eventually taken over by Elsevier. Mendeley is the more polished, functional and useful software. So… Continue reading Zotero vs Mendeley
[Could not find the bibliography file(s) In Memoriam I never had the good fortune of meeting or personally knowing Shoucheng Zhang. Nevertheless he has had a profound influence on my academic career. As the world learned sometime last week, Zhang passed away suddenly on December 1 “after fighting a battle with depression” 1. He was… Continue reading Shoucheng Zhang, 1963-2018
The thermodynamic concept of temperature is defined by the following equation: $$ T = \frac{\partial E}{\partial S} $$ where $ E $ is the energy of the system and $ S $ is the entropy. Now usually when the energy of a system increases or decreases it’s disorder, and hence it’s entropy, also increases or… Continue reading Negative Temperatures
Other 1 than all the other very good theoretical reasons for wanting a theory of quantum gravity, there are some very good practical reasons for wanting such a theory. Ultimately the fate of scientists, theorists and experimentalists alike, rests in the hands of the general public and its elected or appointed political representatives. Why, after… Continue reading Social Relevance of Quantum Gravity
Objects in the rearview mirror may be closer than they seem. This statutory warning is familiar to anyone who has ever ridden in a passenger vehicle. Its intent is to warn the driver and the passengers to be careful while backing up in case the car collides with something which is closer than it actually seems in… Continue reading The Planck Scale May Be Closer Than It Appears
Homogenous Functions A homogenous function of order $n$ satisfies: $$ f(\lambda x_1, \lambda x_2, \ldots, \lambda x_m) =\lambda^n f(x_1, x_2, \ldots, x_m) $$ For e.g. $$ f(x,y) = \sqrt{x} y^2 $$ is homogenous of order $n = 3/2$ . However: $$ f(x,y) = \sqrt x y^2 + x^2 y^2 $$ is not a homogenous function… Continue reading Euler's Homogenous Function Theorem
The area of a charged rotating (Kerr) black hole is given by \begin{equation} \label{eqn:kerr-area-relation} A = 4\pi \left[ 2 M^2 + 2 (M^4 – L^2 – M^2 Q^2)^{1/2} – Q^2 \right] \end{equation} This relation can be inverted to express the mass $M$ as a function of charge $Q$, area $A$ and angular momentum $L$: \begin{equation}… Continue reading Euler's Theorem and the Smarr Relation
So one month ago there was this wonderful workshop on “Optimising, Renormalising, Evolving and Quantising Tensor Networks” – or EVONET18 – organized by the Max Planck Institute for Complex Systems (MPIPKS) in Dresden, Germany. I was fortunate enough to be selected for a poster presentation and had the great privilege of mingling and discussing physics… Continue reading EVONET18 – Tensor Networks for One and All