Theoretical Physicists in India

January 13, 2018 Deepak VaidLeave a comment

There are many research centers and researchers in India working in hep-th (High Energy Physics, Theory), gr-qc (General Relativity/Quantum Cosmology) and quant-ph (Quantum Physics). However they are scattered all over the place and I have not been able to find a place which lists the names of places and individuals working in these fields in… Continue reading Theoretical Physicists in India

Research

Fluctuation Dissipation in Quantum Gravity

August 9, 2017 Deepak VaidLeave a comment

In statistical mechanics we are mostly concerned with the statistical averages of various physical quantities when the system is in equilibrium. Fluctuation is a common phenomenon in nature. Fluctuation means how much a quantity deviates from its average value. The average value of the thermodynamic observables and the size of their fluctuation about their equilibrium… Continue reading Fluctuation Dissipation in Quantum Gravity

Research

Spacetime Geometry as Information Geometry

August 16, 2015 Deepak VaidLeave a comment

In an entry to the 2013 FQXi essay contest and in an accompanying paper, Jonathan Heckman, a postdoc at Harvard, put forward a scintillating new idea – that one can derive the theory of strings and of gravity starting from nothing more but a Bayesian statistical inference model in which a collective of $N$ agents… Continue reading Spacetime Geometry as Information Geometry

Research

Multiverse, multiverse, where art thou?

May 12, 2014 Deepak VaidLeave a comment

As I understand it, the multiverse concept arises as a consequence of the standard inflationary scenario which involves one or more scalar fields “rolling down” the side of a potential hill, causing an exponential increase in the “size” of the Universe soon after the Big Bang. Now the form of the potential itself varies from… Continue reading Multiverse, multiverse, where art thou?

Research

The Measurement Problem, Part 1

July 5, 2013 Deepak VaidLeave a comment

The Problem The measurement problem becomes a problem only when we neglect to specify the nature of the observer’s Hilbert space. Postulates I (Systems are described by vectors in a Hilbert space) and II (Time evolution occurs via some given Hamiltonian for a particular system) are fine in that regard. These two postulates deal only… Continue reading The Measurement Problem, Part 1

Research

Thermal Time and Kepler's Second Law

February 11, 2013 Deepak Vaid2 Comments

In a fascinating recent paper (arXiv:1302.0724), Haggard and Rovelli (HR) discuss the relationship between the concept of thermal time, the Tolman-Ehrenfest effect and the rate of dynamical evolution of a system – i.e., the number of distinguishable (orthogonal) states a given system transitions through in each unit of time. The last of these is also… Continue reading Thermal Time and Kepler's Second Law

General · Politics · Research · Uncategorized

Some things … cannot be learned quickly

January 30, 2013 Deepak VaidQuoteLeave a comment

There are some things which cannot be learned quickly,
and time, which is all we have,
must be paid heavily for their acquiring.
They are the very simplest things,
and because it takes a man’s life to know them
the little new that each man gets from life
is very costly and the only heritage he has to leave.
– Ernest Hemingway (From A. E. Hotchner, Papa Hemingway, Random House, NY, 1966)

Research · Uncategorized

Elementary particles and quantum geometry

January 26, 2013 Deepak VaidLeave a comment

Black holes are formed due to the gravitational collapse of matter – ordinary matter, consisting of the particles and excitations of the Standard Model that we know and love. These include electrons, photons, neutrinos, quarks, mesons etc, and their respective anti-particles. General Relativity tells us that the properties of (macroscopic) black holes are universal, in… Continue reading Elementary particles and quantum geometry

General · Politics · Research · Uncategorized

… and so it begins

January 26, 2013 Deepak VaidLeave a comment

Welcome to my blog, gentle readers. Here you will be exposed to all manner of speculation and conjecture on my part. Those with an enhanced sensitivity to non-rigorous reasoning might occasionally experience a feeling akin to motion sickness. I urge such rigor-bound passengers to depart at the earliest exit. To the rest, welcome aboard. Happy… Continue reading … and so it begins

A Quantum of Gravity

Bringing Quantum Gravity to the masses since 2013

Category: Research

Theoretical Physicists in India

Fluctuation Dissipation in Quantum Gravity

Spacetime Geometry as Information Geometry

Multiverse, multiverse, where art thou?

The Measurement Problem, Part 1

Thermal Time and Kepler's Second Law

Some things … cannot be learned quickly

Elementary particles and quantum geometry

… and so it begins