Topics, Q
Q-Balls
* Idea: Non-topological solitons which exist classically for any fixed value of an
unbroken global charge Q.
@ References: Kusenko PLB(97)
[small charge]; Graham PLB(01)ht [quantum
effects, stability]; Deshaies-Jacques & MacKenzie PRD(06)ht [in
Maxwell-Chern-Simons theory]; Tsumagari PhD(09)-a0910 [formation and stationary properties].
Q-Manifold > see manifolds [supermanifolds].
Q-Stars
@ References: Prikas NPB(04) [in 2+1 dimensions]; PLB(05) [in scalar-tensor theories].
QCD > s.a. QCD phenomenology.
QED > s.a. modified versions and QED phenomenology.
Quadratic Curvature Terms > see higher-order gravity.
Quadratic Equation > see elementary algebra.
Quadratic Form / Function > s.a.
Bilinear Form.
$ Def: A quadratic form
on a vector space V is a function
f : V → R that
can be written as f(v) = 
i
li(v) li'(v),
where li and li'
are linear for all i.
* Relationships: Any
quadratic form defines a positive-definite bilinear
form.
* Sesquilinear form: A quadratic form on a complex vector space, which
is linear in one argument and anti-linear in the other; Used to define (complex)
Hilbert spaces.
@ References: O'Meara 63; Coll & Morales JMP(93) [signature].
Quadrupole Formula > see gravitational radiation.
Quality Factor Q > see oscillator.
Quantions
* Idea: A non-division
algebra; Similarly to quaternions, quantions preserve the core features of
associativity and complex conjugation, while giving up the notion of division;
Has been used as a framework for electroweak theory on curved space-time.
@ References: Moldoveanu a0901 [and unification of quantum mechanics and relativity].
Quantization > see path integrals; quantum mechanics (also canonical, deformed, formalism, geometric, histories, modified, representations, stochastic); Third Quantization.
Quantum Action Principle > see renormalization [algebraic].
Quantum Algebra > s.a. quantum
group.
@ References: Pillin CMP(96)
[deformed Heisenberg algebra]; Jaganathan mp/00-intro, mp/01-in;
Celeghini &
del Olmo EPL-ht/01 [and
quantum theory]; Banica & Collins JGP(08)
[Pauli representation of quantum permutation algebra].
Quantum Billiard > see spectral geometry.
Quantum Carpet
* Idea: A generic spacetime
pattern formed in the probability distributions P(x, t)
of 1D
quantum particles, first discovered in 1995; Related to the Talbot Effect and
to quantum state revivals.
@ References: Hall et al JPA(99)qp [and
travelling waves]; Friesch et al NJP(00); Berry et al pw(01)jun.
Quantum Cosmology > s.a. FRW quantum cosmology.
Quantum Deformation > see deformation quantization; differential geometry; hamiltonian dynamics; quantum particle models.
Quantum Dot > see quantum technology.
Quantum Field Theory > s.a. approaches; effective theories; effects; states; types of theories.
Quantum Field Theory in Curved Spacetime > s.a. various backgrounds and effects.
Quantum Gravity > s.a. 2D; 3D; approaches; canonical; matter phenomenology; semiclassical quantum gravity; ...
Quantum Logic > see logic.
Quantum Mechanics > s.a. effects; experiments; formulations; histories; interpretations; semiclassical; states; systems; ...
Quantum Non-Demolition Experiments > see experiments in quantum mechanics.
Quantum Optics > see optics.
Quantum Potential > see pilot-wave interpretation, potential.
Quantum Spacetime > s.a. proposals.
Quark > see hadrons; QCD phenomenology [including quark-gluon plasma, quark nuggets].
Quark Star > see astronomical objects.
Quarkonium
* Idea: Bound states
of a heavy quark Q = c, b and the corresponding
antiquark.
@ References: Eichten et al RMP(08) [rev].
Quartic Equation > see elementary algebra.
Quasicrystal > see crystals.
Quasifold
* Idea: A space locally
modelled on Rk modulo the action of a discrete, possibly
infinite,
group.
Quasilocal Formulation of Field Theory > see general relativity.
Quasinormal Modes > see black-hole perturbations.
Quasiorder
$ Def: A transitive relation.
* Relationships: A finite
quasiordered set is the same as a finite topological space (> see poset).
* Example: The refinement
relation between covers of a topological space is a reflexive quasiorder (a
direction), but is not antisymmetric.
@ General references: in Isbell 64, p3.
@ Related topics: Ding DM(09) [canonical antichains].
Quasiparticles > s.a. particle
types; Phonon; Roton.
* Idea: A composite object
produced when one "immerses" a particle in a quantum many-body system, for
instance an electron in a solid; The particle "swims" shrouded
by a cloud of excitations of its new environment, which modifies its physical
properties (mass, charge, etc.).
@ Bogoliubov quasiparticles: Zhang et al PRL(06)cm/05,
Horvath et al cm/05 [in
a superfluid].
@ Other types: Schirotzek et al PRL(09)
+ Chevy Phy(09)
[fermionic analog of a solid-state polaron].
Quasiperiodic Tiling > see crystals [quasicrystals]; tilings.
Quasiset Theory > s.a. locality.
* Idea: The mathematical
theory of collections of indistinguishable objects
@ General references: Sant'Anna qp/04 [and
undecidable finite sets].
@ And identical particles: Sant'Anna qp/98, & Santos
FP(00)qp/99;
Sant'Anna qp/04;
Domenech & Holik FP(07)-a0705;
Domenech et al FP(08)-a0803.
> Online resources: Wikipedia page.
Quasispherical Metric > see types of metrics.
Quaternions > s.a. SU(2).
* Idea: May be written as ordered pairs of complex numbers, or as
H = {a + i b + j c + k d | a, b,
c, d 
R}
,
with i2 = j2 =
k2 = –1, i · j = – j · i
=
k and cyclic permutations; i, j, k can be represented using Pauli matrices
by i
2,
i2,
and i1,
respectively.
* Relationships: The
unit quaternions are isomorphic to SU(2), topologically S3.
@ General references: Aslaksen MI(96) [matrix
determinants]; Kravchenko et al mp/01 [quaternionic
Riccati equation]; De Leo et al
JMP(02)mp [eigenvalue
problems]; De Leo & Ducati JMP(03)mp [quaternionic
differential equations]; Conway
& Smith.
@ Generalizations:
Liu mp/01 [biquaternions];
Raptis mp/01 [graded,
deformed].
@ In cosmology: Misner in(94) [mixmaster]; Brumby et al PLB(97) [dark
matter]; Majerník GRG(04)ap/03,
GRG(03)
[dark energy].
@ In physics: Robinson JMP(91)
[4D conformal structure]; Lambek MI(95); De Leo IJTP(96)ht/95 [guts], & Rodrigues
IJTP(98),
IJTP(98)
[Dirac electrons], & Ducati
IJTP(99)ht;
Vandoren ht/00-in
[Yang-Mills instantons]; Gsponer & Hurni
mp/02-in
[general], mp/05,
mp/05 [bibliography];
Schwartz JMP(06)ht,
JMP(07)ht [wave
equation]; Maia et al FP(09)-a0809 [and
quantum gravity]; Graf a0811 [and
dynamics, introduction].
>
In physics: see modified
quantum mechanics; modified quantum field theories; special relativity; spinors; spin-3/2
field theories.
Qubit, Qudit > see quantum systems.
Quillen Determinant
@ References: Furutani JGP(04) [line bundle].
Quintic Equation > see elementary algebra.
Quintom Dark Energy
* Idea: A hybrid of quintessence
and phantom dark energy which involves the participation of two real scalar
fields playing the roles of those two types of dark energy.
@ Cosmology: Lazkoz & León PLB(06).
Quiver Varieties
@ References: Ginzburg m.QA/00.
Quons > see particle statistics.
Quotient Function
$ Def: The function Q(x):=
(1–x)/(1+x).
@ References: Lindell & Sihvola AJP(98)mar
[applications].
main page – abbreviations – journals – comments – other
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send feedback and suggestions to bombelli at olemiss.edu – modified
21 oct 2009