Part I: Understanding String Theory
... is as follows: It is a GUT that proposes everything is made up out tiny one dimensional
string of energy that can move in 10 dimensions .
The geometry of the strings being either open string or closed loops and the various
ways in which these may vibrate gives rise to all the complexity we experi ...
underdetermination and theory succession from the perspective of
... The current status of string theory looks even more remarkable when one considers the
theory’s future prospects: today, about 30 years after its creation, string theory still lacks any
realistic prospect of becoming experimentally testable. The characteristic experimental
signatures of string theory ...
... What is the significance of topological order?
Globel danicing pattern is a nice picture for topological order.
But does it mean anything?
Does topological order have any experiemntal significance?
Does topological order have any new experiemntal properties,
that is different from any symmetry brea ...
talk_pacific - University of Kentucky
... This fluctuating nature is most naturally expressed in
Feynman’s path integral formulation of quantum theory.
Consider a Quantum-Mechanical particle described by
Hamiltonian H and corresponding classical action S.
The Internal and External Problems of String Theory
... that of a mathematically inspired metaphysics of nature?
An adequate answer to these questions is certainly not to be expected from physics; physics does
not have the methodology to answer such metatheoretical questions. These are undoubtedly
questions to be answered in the context of philosophy of ...
Harmony of Scattering Amplitudes: From gauge theory
... 3) Interesting hint from string dualities. Chalmers; Green, Vanhove, Russo
– Dualities restrict form of effective action. May prevent
divergences from appearing in D = 4 supergravity, athough
issues with decoupling of towers of massive states and indirect.
URL - StealthSkater
... The string word sheets are uniquely identified as inverse images under imbedding map of
space-time surface to H=M4×CP2 of homologically non-trivial geodesic sphere of CP2 defining
homological magnetic monopole. Holography in its strongest sense states that all information
about non-trivial 2-homolog ...
... • Strings: particles in string theory arise as excitations of the string, and included in the excitations of a
string. A "1-brane," is a string.
• Brane: Short for membrane. a higher-dimensional manifold moving in spacetime.
• D-brane; D-branes are a class of extended objects upon which open strings ...
Recent Developments in String Theory
... necessarily appear, which means that this kind of string theories imply gravity. This fact
has been one of the main motivations for studying string theory.
Fermions (thought as “quarks” and “leptons”) are obtained by suitably choosing the
boundary conditions of the two dimensional fermions ψ on Σ. T ...
... Conservation laws and Scattering in 1+1 dimensions
local conserved charges
Equivalence of Topological Codes and Fast Decoding
... To define precisely what we mean by local, consider
an operator P acting on some qubits contained within a
region of finite radius r. Then, a unitary transformation
U is a local mapping if U P U † is contained within a region
of radius less or equal to r + c, where c is a constant.
This result is im ...
F From Vibrating Strings to a Unified Theory of All Interactions
... with abstract field theoretic concepts, 8.251 started
rooted in the physics that we were all familiar with: the
mechanics of a simple string. It all started there and
quickly went through many iterations until arriving at
the quantum mechanics of relativistic strings. Though
at times the math was di ...
URL - StealthSkater
... classical electroweak and color fields correspond to induced metric and induced gauge fields in TGD
framework. The fundamental field space becomes essentially compact CP2 whereas for ordinary gauge
potentials the field space is non-compact affine space.
This means that the imbedding of, say, constan ...
fundamental_reality\Black hole war
... Strings have entropy. The presence of a photon represents one single bit of information.
As more energy is pumped into the photon, it becomes a string with thermal jitters. The
tangle of the string is too complicated to describe in detail, but a rough description is
possible. This is the “hidden inf ...
The Excitement of Scattering Amplitudes
... Amplitude excitement
• Field interesting in its own right: new insights into QFT?
• Solve all order amplitudes in planar N=4 SYM?
• Relevant for particle physics processes at the LHC.
• Fundamental physics applications:
Origin of simple structure in string theory?
• New method ...
Strings as hadrons
... magnitude and therefore completely abandon the idea that progress in physics proceeds incrementally.
Heady stuff. But also the source of much irritation in the rest of the physics community.
Another reason for annoyance was somebody's idea to start referring to string theory as a "Theory of
The Elegant Universe: Part 2
... MICHAEL DUFF (University of Michigan): We work on the assumption that there is a theory out there, and it's our
job, if we're sufficiently smart and sufficiently industrious, to figure out what it is.
STEVEN WEINBERG (University of Texas at Austin): We don't have a guarantee—it isn't written in the ...
string theory: big problem for small size
... The original string theory developed in the period 1968–70 was known as bosonic
string theory. The main disadvantages of this theory were: (i) it needs 26-dimensional
space-time, (ii) the absence of fermions in the theory, and (iii) the existence of a
particle with imaginary mass, called tachyon, ge ...
Broken symmetry revisited - Homepages of UvA/FNWI staff
... Also, an important effect on the spectrum and the interactions of a theory with a
broken gauge group is caused by the introduction of additional topological terms in
the action, such as a nonvanishing θ angle in 3+1 dimensional space time and the
Chern-Simons term in 2+1 dimensions. It has been show ...
... caught up with experiment. In the absence of new data, physicists must steer by something other
than hard empirical evidence in their quest for a final theory. And that something they call
“beauty.” But in physics, as in the rest of life, beauty can be a slippery thing.
The gold standard for beauty ...
... String theory can be formulated on any background. String quantisation probes
nearby backgrounds. Low-energy physics depends on classical background. Full
quantum string theory is background independent, contains all backgrounds as
Gravity, Particle Physics and Their Unification 1 Introduction
... far away, it looks like a pointlike object. These diﬀerent oscillatory states of the
string are analogous to the diﬀerent polarization states of the particles. Note
that the mass of the string state itself depends on the “polarization” state. Some
of these oscillatory states of the string will have ...
Topological string theory
In theoretical physics, topological string theory is a simplified version of string theory. The operators in topological string theory represent the algebra of operators in the full string theory that preserve a certain amount of supersymmetry. Topological string theory is obtained by a topological twist of the worldsheet description of ordinary string theory: the operators are given different spins. The operation is fully analogous to the construction of topological field theory which is a related concept. Consequently, there are no local degrees of freedom in topological string theory.There are two main versions of topological string theory: the topological A-model and the topological B-model. The results of the calculations in topological string theory generically encode all holomorphic quantities within the full string theory whose values are protected by spacetime supersymmetry. Various calculations in topological string theory are closely related to Chern–Simons theory, Gromov–Witten invariants, mirror symmetry, geometric Langlands Program, and many other topics.Topological string theory was established and is studied by physicists such as Edward Witten and Cumrun Vafa.