Updated Lectures till 15th Nov 25

_config.yml

@@ -107,6 +107,16 @@ defaults:
       type: lectures
     values:
       topic: "Differential Geometry"
+  - scope:
+      path: "_lectures/group-theory"
+      type: lectures
+    values:
+      topic: "Group Theory"
+  - scope:
+      path: "_lectures/quantum-mechanics"
+      type: lectures
+    values:
+      topic: "Quantum Mechanics"
   - scope:
       path: "_lectures/other-topics"
       type: lectures

_events/2025-11-15-major-selection-talk.md

@@ -0,0 +1,21 @@
+---
+title: O Captains! My Captains! Welcome to the Dead Physicists' Society
+layout: post
+author: Ritabrata Ghosh
+---
+
+Major Selection Talk for Physics majors
+
+<!--more-->
+
+After hearing from all other majors, it's time to hear about the major that you'll take anyways!
+
+You, Sophomores, are at a crossroads today. You're being told to be practical, to be realistic, to choose an easy path. But we don't do Physics because it's easy. We study physics because we are members of the human race. And the human race is filled with passion. Chemistry, Biology, Maths, Materials; these are noble pursuits and necessary to sustain life. But physics, beauty, curiosity, wonder... these are what we stay alive for.
+
+So meet with us, the upper-year ghosts of the Dead Physicists' Society, on 15th Nov from **9:30pm** at **F-08A**, where we will:
+Stand on our desks (metaphorically... probably) to show you how to look at physics in a new light.
+Discuss the courses: The "Carpe Diems" (the ones to seize!) and the "Caveat Emptors" (the ones to... approach with caution).
+Share our 'why': Why we chose this path and why, despite the all-nighters, we’d do it all again (I guess).
+Answer your questions: No holds barred. Ask us about research, courses, life, lab reports, or which energy drink to pick for solving those integrals!
+
+So let's gather for the Physics Major Selection Meeting. No we don't have pizzas to offer you. We just have our enthusiasm. With this enthusiasm, we would write you a weird announcement with a movie reference when we have a quiz to prepare for the next day. But you are not nerdy enough to understand that! 

_lectures/differential-geometry/2025-10-27-differential-geometry-2.md

@@ -3,6 +3,7 @@ title: Differential Geometry 2
 author: Simar Narula
 layout: post
 image: /assets/img/posts/differential_geometry_2/poster.webp
+slides: /assets/files/Diff-Geo-lec2.pdf
 # topic: "Differential Geometry"    
 ---
 

_lectures/differential-geometry/2025-11-05-differential-geometry-3.md

@@ -0,0 +1,18 @@
+---
+title: Differential Geometry 3
+author: Simar Narula
+layout: post
+image: /assets/img/posts/differential_geometry_3/poster.webp
+# topic: "Differential Geometry"    
+---
+
+
+<!--more-->
+In the third lecture, we will continue from where we left off in the last lecture and complete the formalism of the tangent space. After this, we will extend the idea of vectors and tensors defined at a point to vector and tensor fields over the whole manifold. We will then go on to discuss a special class of tensors called differential forms, and define the wedge product and the Hodge dual. Following this, we will introduce the operations of exterior differentiation and the Lie derivative. We will then add another structure to our smooth manifold, the covariant derivative, and discuss its implications. We will see that the curvature of the space depends on the notion of covariant derivative defined on it. If time allows, we will also discuss the torsion tensor and the Riemann curvature tensor.
+
+
+## Details of the session:  
+Speaker: **Simar Narula (3rd Year UG)**  
+Date: **5th November (Wednesday)**  
+Time: **2:00 PM**  
+Venue: **F-08A, OPB**  

_lectures/group-theory/2025-10-31-group-theory-1.md

@@ -0,0 +1,21 @@
+---
+title: Group Theory 1
+author: Sriraj Chandra
+layout: post
+image: /assets/img/posts/group-theory-1/poster.webp
+slides: /assets/files/Group_Theory_Lec_1.pdf
+# topic: "Group Theory"    
+---
+
+
+<!--more-->
+We are excited to announce a session on Group Theory, a subject that forms the mathematical backbone of many areas in physics. In this lecture, we will talk about the group theory concepts essential for physics, ideas that form the mathematical foundation of symmetry, conservation laws, and particle physics.
+
+We will begin with basic definitions in abstract algebra such as groups, rings, and modules, and explore some of the fundamental properties that arise from these structures. Then, we will motivate the use of group theory in physics through several well-known examples and applications. Finally, we will discuss the representation theory of finite groups and its relevance in physical systems. If time permits, we will also introduce Lie groups and their connection to manifolds.
+
+## Details of the session:  
+Speaker: **Sriraj Chandra (3rd Year UG)**  
+Date: **31st October (Friday)**  
+Time: **6:30 PM**  
+Venue: **F-08A, OPB**  
+

_lectures/group-theory/2025-11-04-group-theory-2.md

@@ -0,0 +1,18 @@
+---
+title: Group Theory 2
+author: Sriraj Chandra
+layout: post
+image: /assets/img/posts/group-theory-2/poster.webp
+slides: /assets/files/Group_Theory_Lec_2.pdf
+# topic: "Group Theory"    
+---
+
+
+<!--more-->
+In the second lecture of Group Theory, we will begin with a recap of the basic definitions in representation theory. Then, we'll move on to a discussion of various important results for representations of finite groups, notably Schur's lemma. Then, we'll discuss character tables and their use in various physical problems. Finally, we'll introduce Lie groups and begin a discussion of their various properties. If time permits, we'll derive the Baker-Campbell-Hausdorff lemma.
+
+## Details of the session:  
+Speaker: **Sriraj Chandra (3rd Year UG)**  
+Date: **4th November (Tuesday)**  
+Time: **6:15 PM**  
+Venue: **F-08A, OPB**  

_lectures/group-theory/index.md

@@ -0,0 +1,5 @@
+---
+layout: topic-page
+permalink: '/lectures/group-theory/'
+title: Group Theory
+---

_lectures/other-topics/2025-11-09-percolation-universality-and-coarsening.md

@@ -0,0 +1,29 @@
+---
+title: Percolation, Universality and Coarsening
+author: Panchariya Chinmay Anil
+layout: post
+image: /assets/img/posts/percolation/poster.webp
+slides: /assets/files/Percolation.pdf
+---
+
+Talk on percolation, universality and coarsening
+
+<!--more-->
+
+## Synopsis
+
+After performing random walks through Differential Geometry, Quantum Mechanics, and Group Theory, it’s time to let some Statistical Mechanics percolate through you.
+
+If we build a maze by randomly connecting corridors, what is the probability that an ant can wander forever without hitting a dead end? Or, in a forest, what is the minimum density of trees required before a small spark inevitably grows into an uncontainable wildfire?
+Questions like these lead us to Percolation Theory.
+
+In this talk, we will begin by introducing the basic ideas of percolation and exploring various percolation models, highlighting their surprisingly broad range of applications beyond physics. We will then analyze the 1D percolation model, where the notions of critical points and critical exponents naturally emerge. At the critical threshold, we will see how purely geometric phase transitions arise and discuss Peierls’ argument, which provides bounds on such critical points.
+In the second half, we will explore the powerful concept of universality: the observation that systems which look completely different microscopically can exhibit identical behaviour near their critical point, provided they share the same symmetry and dimensionality. Finally, we will introduce the idea of coarse-graining and develop an intuitive understanding of the Renormalization Group (RG), connecting back to the themes of scaling and universality that run throughout percolation theory.
+The mathematical discussion in the talk will be kept at a basic level, with no prerequisites required!
+
+
+## Details of the session:  
+Speaker: **Panchariya Chinmay Anil (3rd Year UG)**  
+Date: **9th November (Sunday)**  
+Time: **2:30 PM**  
+Venue: **F-08A, OPB** 

_lectures/quantum-mechanics/2025-11-01-quantum-mechanics-1.md

@@ -0,0 +1,19 @@
+---
+title: Quantum Mechanics 1
+author: Ritabrata Ghosh
+layout: post
+image: /assets/img/posts/qm_1/poster.webp
+# topic: "Quantum Mechanics"    
+---
+
+
+<!--more-->
+We are pleased to announce a lecture series on Quantum Mechanics, one of the most profound and beautiful theory in physics, with applications across almost all branches of modern science. This series aims to provide the audience with sufficient training to use this powerful framework with appreciable comfort.
+
+In this first lecture, we will try to start our venture into Quantum Mechanics by formally understanding the postulates of QM. We'll digress a little to talk about Hilbert Spaces, with a very light discussion on a few types of Hilbert spaces that is of interest to QM. This discussion will largely bypass the rich mathematical rigour of the formal definitions of the theory but would provide a starting point for the interested learner. We'll try to develop a recipe to tackle any dynamical problem of QM. We will also discuss the different "pictures" of QM. If time permits, we will try to study the dynamics explicitly for a few potentials and/or give an intro to the density matrix formalism. The Dirac notation, which was introduced in the Linear Algebra talk series by Ensemble, will be used freely. This lecture is majorly aimed towards the first and second year UGs.
+
+## Details of the session:  
+Speaker: **Ritabrata Ghosh (3rd Year UG)**  
+Date: **1st November (Saturday)**  
+Time: **9:15 PM**  
+Venue: **F-08A, OPB**  

_lectures/quantum-mechanics/2025-11-02-quantum-mechanics-2.md

@@ -0,0 +1,18 @@
+---
+title: Quantum Mechanics 2
+author: Ritabrata Ghosh
+layout: post
+image: /assets/img/posts/qm_2/poster.webp
+slides: /assets/files/QMlec2.ipynb
+# topic: "Quantum Mechanics"    
+---
+
+
+<!--more-->
+In the second lecture of Quantum Mechanics, we will pick up from where we left in the last lecture. We will discuss an example that will use concepts we have developed so far. Then we venture into the last postulate describing the evolution of a quantum state in time. We'll discuss the different pictures of QM. And then we take up a few potentials and solve the dynamics of the system explicitly for them. If time permits, I'll try to show a simulation of one of the cases we discussed. We will either stop here or set up the stage for a proper analysis of the Quantum Harmonic Oscillator.
+
+## Details of the session:  
+Speaker: **Ritabrata Ghosh (3rd Year UG)**  
+Date: **2nd November (Sunday)**  
+Time: **6:00 PM**  
+Venue: **F-08A, OPB**  

_lectures/quantum-mechanics/2025-11-05-quantum-mechanics-3.md

@@ -0,0 +1,17 @@
+---
+title: Quantum Mechanics 3
+author: Ritabrata Ghosh
+layout: post
+image: /assets/img/posts/qm_3/poster.webp
+# topic: "Quantum Mechanics"    
+---
+
+
+<!--more-->
+Following our experiments with the Gaussian Wave Packet in the last class, we'll draw a few more inferences from it which will push us into a discussion on Ehrenfest Theorem and its validity. We'll also discuss why we get a deviation from Ehrenfest Theorem in the simulation we played with in the last lecture. After this, we will start with the treatment of the Quantum Harmonic Oscillator, one of the most widely used potentials. Depending on the time and interest, we can either digress to talk about the Quantum Anharmonic Oscillator (You might see one application of the Poschl-Teller Potential that we discussed in last class) or skip this to start the Spin Algebra.
+
+## Details of the session:  
+Speaker: **Ritabrata Ghosh (3rd Year UG)**  
+Date: **5th November (Wednesday)**  
+Time: **10:00 AM**  
+Venue: **F-08A, OPB**  

_lectures/quantum-mechanics/index.md

@@ -0,0 +1,5 @@
+---
+layout: topic-page
+permalink: '/lectures/quantum-mechanics/'
+title: Quantum Mechanics
+---