PhyslibSearch

Physlib.Relativity.LorentzGroup.Proper

20 declarations

theorem

det(Λ)=±1\det(\Lambda) = \pm 1 for ΛLd\Lambda \in \mathcal{L}_d

#det_eq_one_or_neg_one

Let Ld\mathcal{L}_d denote the Lorentz group acting on a (1+d)(1+d)-dimensional Minkowski space. For any element ΛLd\Lambda \in \mathcal{L}_d, the determinant of its matrix representation is either 11 or 1-1. That is, det(Λ)=1ordet(Λ)=1.\det(\Lambda) = 1 \quad \text{or} \quad \det(\Lambda) = -1.

instance

Discrete topology on Z2\mathbb{Z}_2

#instTopologicalSpaceMultiplicativeZModOfNatNat

The definition provides a topological space structure on the group Z2\mathbb{Z}_2 (the cyclic group of order 2), where the topology assigned is the discrete topology.

instance

Z2\mathbb{Z}_2 is a discrete space

#instDiscreteTopologyMultiplicativeZModOfNatNat

The topological space defined on the group Z2\mathbb{Z}_2 (the cyclic group of order 2) is a discrete space.

instance

Z2\mathbb{Z}_2 is a topological group

#instIsTopologicalGroupMultiplicativeZModOfNatNat

The cyclic group of order 2, Z2\mathbb{Z}_2, is a topological group when equipped with the discrete topology. This implies that the group multiplication and inversion operations are continuous maps.

definition

Continuous map from {1,1}\{-1, 1\} to Z2\mathbb{Z}_2

#coeForℤ₂

The function is a continuous map f:{1,1}Z2f: \{-1, 1\} \to \mathbb{Z}_2, where the domain {1,1}\{-1, 1\} is a subset of the real numbers R\mathbb{R} and Z2\mathbb{Z}_2 is the cyclic group of order 2. The map is defined such that f(1)f(1) is the identity element of Z2\mathbb{Z}_2 (corresponding to 0Z/2Z0 \in \mathbb{Z}/2\mathbb{Z}) and f(1)f(-1) is the non-identity element of Z2\mathbb{Z}_2 (corresponding to 1Z/2Z1 \in \mathbb{Z}/2\mathbb{Z}).

definition

Continuous determinant map det:LdZ2\det: \mathcal{L}_d \to \mathbb{Z}_2

#detContinuous

The continuous map det:LdZ2\det: \mathcal{L}_d \to \mathbb{Z}_2 from the Lorentz group Ld\mathcal{L}_d to the cyclic group of order 2. For a Lorentz matrix Λ\Lambda, it maps the determinant det(Λ){1,1}\det(\Lambda) \in \{-1, 1\} to the corresponding element in Z2\mathbb{Z}_2, where det(Λ)=1\det(\Lambda) = 1 corresponds to the identity element and det(Λ)=1\det(\Lambda) = -1 corresponds to the non-identity element.

theorem

detcont(Λ)=1    det(Λ)=1\det_{\text{cont}}(\Lambda) = 1 \iff \det(\Lambda) = 1

#detContinuous_eq_one

For any element Λ\Lambda in the Lorentz group Ld\mathcal{L}_d, the continuous determinant map det:LdZ2\det: \mathcal{L}_d \to \mathbb{Z}_2 evaluates to the identity element of Z2\mathbb{Z}_2 if and only if the determinant of the matrix Λ\Lambda is 11.

theorem

detcont(Λ)=1    det(Λ)=1\det_{\text{cont}}(\Lambda) = -1 \iff \det(\Lambda) = -1

#detContinuous_eq_zero

For any element Λ\Lambda in the Lorentz group Ld\mathcal{L}_d acting on (1+d)(1+d)-dimensional Minkowski space, the continuous determinant map detcont:LdZ2\det_{\text{cont}}: \mathcal{L}_d \to \mathbb{Z}_2 evaluates to the non-identity element of Z2\mathbb{Z}_2 if and only if the determinant of the matrix representation of Λ\Lambda is 1-1.

theorem

detcont(Λ)=detcont(Λ)    det(Λ)=det(Λ)\det_{\text{cont}}(\Lambda) = \det_{\text{cont}}(\Lambda') \iff \det(\Lambda) = \det(\Lambda')

#detContinuous_eq_iff_det_eq

For any elements Λ\Lambda and Λ\Lambda' in the Lorentz group Ld\mathcal{L}_d, the values of the continuous determinant map detcont:LdZ2\det_{\text{cont}}: \mathcal{L}_d \to \mathbb{Z}_2 are equal if and only if the determinants of their matrix representations are equal. That is, detcont(Λ)=detcont(Λ)    det(Λ)=det(Λ).\det_{\text{cont}}(\Lambda) = \det_{\text{cont}}(\Lambda') \iff \det(\Lambda) = \det(\Lambda').

definition

Determinant representation det:LdZ2\det: \mathcal{L}_d \to \mathbb{Z}_2

#detRep

The group homomorphism det:LdZ2\det: \mathcal{L}_d \to \mathbb{Z}_2 from the Lorentz group Ld\mathcal{L}_d to the cyclic group of order 2. For any Lorentz transformation ΛLd\Lambda \in \mathcal{L}_d, the map sends Λ\Lambda to its determinant det(Λ){1,1}\det(\Lambda) \in \{1, -1\}, represented as an element of Z2\mathbb{Z}_2. Specifically, a determinant of 11 corresponds to the identity element of Z2\mathbb{Z}_2, and a determinant of 1-1 corresponds to the non-identity element.

theorem

The determinant representation detRep:LdZ2\text{detRep}: \mathcal{L}_d \to \mathbb{Z}_2 is continuous

#detRep_continuous

Let Ld\mathcal{L}_d be the dd-dimensional Lorentz group and Z2\mathbb{Z}_2 be the cyclic group of order 2 equipped with the discrete topology. The determinant representation detRep:LdZ2\text{detRep}: \mathcal{L}_d \to \mathbb{Z}_2, which maps a Lorentz transformation Λ\Lambda to its determinant det(Λ){1,1}\det(\Lambda) \in \{1, -1\} represented in Z2\mathbb{Z}_2, is continuous.

theorem

det(Λ)=det(Λ)\det(\Lambda) = \det(\Lambda') for ΛconnectedComponent(Λ)\Lambda' \in \text{connectedComponent}(\Lambda)

#det_on_connected_component

For any two Lorentz transformations Λ\Lambda and Λ\Lambda' in the Lorentz group Ld\mathcal{L}_d (the group of linear transformations preserving the Lorentz metric in dd dimensions), if Λ\Lambda' belongs to the same connected component as Λ\Lambda, then their determinants are equal: det(Λ)=det(Λ)\det(\Lambda) = \det(\Lambda').

theorem

detRep(Λ)=detRep(Λ)\text{detRep}(\Lambda) = \text{detRep}(\Lambda') for Λ\Lambda' in the same connected component as Λ\Lambda

#detRep_on_connected_component

Let Ld\mathcal{L}_d be the Lorentz group in dd dimensions. For any two Lorentz transformations Λ,ΛLd\Lambda, \Lambda' \in \mathcal{L}_d, if Λ\Lambda' belongs to the same connected component as Λ\Lambda, then their images under the determinant representation detRep:LdZ2\text{detRep}: \mathcal{L}_d \to \mathbb{Z}_2 are equal, i.e., detRep(Λ)=detRep(Λ)\text{detRep}(\Lambda) = \text{detRep}(\Lambda').

theorem

det(Λ)=det(Λ)\det(\Lambda) = \det(\Lambda') for Lorentz transformations joined by a path

#det_of_joined

For any two Lorentz transformations Λ\Lambda and Λ\Lambda' in the dd-dimensional Lorentz group, if Λ\Lambda and Λ\Lambda' are joined by a path, then their determinants are equal: det(Λ)=det(Λ)\det(\Lambda) = \det(\Lambda').

definition

Proper Lorentz transformation (detΛ=1\det \Lambda = 1)

#IsProper

For a Lorentz transformation Λ\Lambda in the Lorentz group of dimension dd, the property IsProper(Λ)\text{IsProper}(\Lambda) holds if the determinant of the matrix representation of Λ\Lambda is equal to 11, denoted as det(Λ)=1\det(\Lambda) = 1.

instance

Decidability of the proper Lorentz transformation predicate (detΛ=1\det \Lambda = 1)

#instDecidablePredElemMatrixSumFinOfNatNatRealIsProper

For a Lorentz transformation Λ\Lambda in the Lorentz group of dimension dd, the property IsProper(Λ)\text{IsProper}(\Lambda), which is defined by the condition that the determinant of the matrix representation of Λ\Lambda is equal to 11 (det(Λ)=1\det(\Lambda) = 1), is a decidable predicate.

theorem

Product of proper Lorentz transformations is proper

#isProper_mul

For any two Lorentz transformations Λ\Lambda and Λ\Lambda' in the Lorentz group of dimension dd, if Λ\Lambda and Λ\Lambda' are proper transformations (meaning detΛ=1\det \Lambda = 1 and detΛ=1\det \Lambda' = 1), then their product ΛΛ\Lambda \Lambda' is also a proper Lorentz transformation.

theorem

IsProper Λ    detRep Λ=1\text{IsProper } \Lambda \iff \text{detRep } \Lambda = 1

#isProper_iff

For any Lorentz transformation Λ\Lambda in the Lorentz group Ld\mathcal{L}_d of dimension dd, Λ\Lambda is a proper Lorentz transformation (IsProper Λ\text{IsProper } \Lambda) if and only if its image under the determinant representation detRep:LdZ2\text{detRep}: \mathcal{L}_d \to \mathbb{Z}_2 is the identity element 11.

theorem

The Identity Lorentz Transformation is Proper

#isProper_id

The identity element of the Lorentz group in dd dimensions is a proper Lorentz transformation (i.e., its determinant is equal to 11).

theorem

IsProper Λ    IsProper Λ\text{IsProper } \Lambda \iff \text{IsProper } \Lambda' for Transformations in the Same Connected Component

#isProper_on_connected_component

For any two Lorentz transformations Λ\Lambda and Λ\Lambda' in the Lorentz group of dimension dd, if Λ\Lambda' belongs to the same connected component as Λ\Lambda, then Λ\Lambda is a proper Lorentz transformation if and only if Λ\Lambda' is a proper Lorentz transformation. A Lorentz transformation is called proper if its determinant is equal to 11.