Can we discuss multiplication rule of A4 group ?

elements are written in terms of generators S and T 1 , S, T, ST, TS, T2, STS, ,TST, T2ST, TST2, T2S, ST2 How do I multiply S with T2ST from left How do I multiply S with TST2 from left

09 October 2017 4,792 19 View

How to connect quantum field theory with quantum statistical mechanics?

Quantum field theories use Minkowski space whereas statictical mechanics uses 3-D Euclidean space with temperature as an additional variable. Both the theories deal with many particle systems and...

06 July 2015 3,642 2 View

What is microcausality in a quantum field theory?

We know in quantum mechanics position and momentum of a particle do not commute. But in a quantum field theory they must commute if position operator and momentum operator are separated by a space...

06 July 2015 761 46 View

Can we discuss some simple examples of non-local interactions in extra dimensional models ?

Action at a distance is the simplest non-local interaction. But then in relativistic local field theories signals cannot travel at velocities more than the speed of light. This is taken into...

05 June 2015 4,329 15 View

Why two additional Majorana phases are introduced in lepton mixing matrix?

We do not know whether the neutrino is a Dirac particle or a Majorana particle. If neutrino turns out to be a Majorana particle then two additional phases are to be introduced in the 3x3 lepton...

04 May 2015 2,457 18 View

We know that CP violation leads to T violation as CPT is conserved. Does it also imply the existence of an arrow of time in particle interactions?

CPT is a symmetry of fundamental interactions. Therefore CPT conservation is built into relativistic quantum field theories, such as electroweak theory. However we know that CP is violated in weak...

04 May 2015 7,324 15 View

What is luminosity distance ?

What is the definition of luminosity distance? What is the motivation behind defining this term? How it is affected by (i) Space time curvature (ii) Redshift (iii) Time dilation

06 July 2014 5,872 0 View

Why are applications of group theory needed in the study of Physics in general?

Group theory finds wide applications in Physics. A branch of Mathematics becomes useful in the description of physical phenomenon, both classical and quantum, happening around us. What are...

05 June 2014 3,960 45 View

Why was the Newtonian notion of "action at a distance" replaced by local interactions in Einstein's gravity?

In Newtonian notion force between to masses m1 and m2 separated by a distance d is simply G m1 m2/d^2. This is an example of a theory which accepts action at a distance. A second example is...

05 June 2014 1,240 41 View

How the cosmological deceleration parameter is measured in experiments, or, how do we know that the universe is accelerating at present ?

There are a few basic parameters by which the cosmologists try to describe our universe. In classical cosmology the important ones are (i) Hubble parameter (ii) Density parameter (iii)...

05 June 2014 5,158 3 View

MD MOE RMSD

How to calculate the RMSD values for a MD simulation using MOE?

07 August 2021 0 0 View

MD MOE RMSD

How to calculate the RMSD values for a MD simulation using MOE?

07 August 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 3 View

Could you recommend any books about Number Theory?

Beginner level books. High level books. Analytical Number Theory. Algebraic Number Theory. Combinatorical Number Theory. Books about partitions. Books about primes.

03 March 2021 7,174 5 View

Looking for Materials with high thermal expansion coefficient and high temperature resistance?

03 March 2021 8,272 1 View

Can we classify HV and LV lines based on line length?

I have dataset which shows the length of power lines. I need to classify the lines based on the line length. Is there a rule to classify the High voltage (HV) and low voltage (LV) lines based on...

03 March 2021 4,116 4 View