Overall or cosmological time in this paper means there is the same ‘time’ for the physical universe together and no part is late or early in reference to this ‘time’: anything is simultaneous with any other thing. One can suggest overall time can be measured depending on some agreement of universal with ‘local’ properties, e. g. by measuring ‘local’ temperature or radiation properties to agree with or indicate overall cosmological time, and assuming place- or measurement independent overall simultaneity.
However, time within the time interval only description needs to be independent of one moment time set properties. Not is meant time is a zero-dimensional concept without development and not is meant reference can be variable or chosen. Neither is meant a one moment time description parameter for the whole universe, introducing uncertainties from QM or simultaneity or signaling from GR.
Simultaneity is meant to be measurement event ∆t dependent, and for the time interval only description is defined with the introduction of star-source radiation waves, with finite group-velocity and emitted and ‘on the way’ during ∆t, (Hollestelle, 2020), while ∆t being simply measurable or not, a term discussed in comment F.
For one moment time coordinates, derivatives depend on linear addition and the method of tangents. Continuous and invariant time development within the one moment time set means at any ‘time-lapse’ a similar ‘time-lapse’ is added. From this one can introduce one moment time invariant quantities, for instance Noether charges.
One moment time equilibrium including the principle of least action implies application of one moment time coordinate variation, with invariant transit space end-coordinates and variable transit time, i. e. ∆* variation, not to be confused with time interval indication ∆ or ∆t, (Hollestelle, 2020). For symmetric and infinite ∆t, time interval set results are the same as those for one moment time set results, and time interval derivatives are similarly linear addition related. For the time interval only description and TE equilibrium, derivatives imply non-trivial, i. e. non-linear, time interval addition.
The ‘addition zero’ ∆t0 for the time interval set at least can be relevant event time interval ∆t itself, comment 2 and 3, there is A [∆t1, ∆t] = ∆t1. This depends on the premise that there is only ‘one’ ‘time’ for the cosmological universe together and all is at the same ‘time’ and nothing is late or early.
This is valid for any time interval ∆t1 within the time interval only set. This confirms the interpretation of time interval only set addition with domain addition where addition of two identical domains results in the same domain.
Within the time interval only description events and addition properties depend on the relevant event time interval ∆t, equal to ‘addition zero’ ∆t0 for asymmetric ∆t, with A [∆t, ∆t] = ∆t and A [∆t1, ∆t] = ∆t1. The ‘addition inverse’ ∆tiv for the finite relevant event time interval ∆t equals ∆t, meaning A [∆tiv, ∆t] = A [∆t, ∆t] = ∆t.
Multiplication -1. ∆t does not always equal ∆tiv and its definition from eq. 9 fails, meaning it is not a well-defined time interval. One can argue ∆t ‘addition’ -1. ∆t equals -1. ∆t from the above discussion where ‘addition zero’ ∆t0 equals ∆t. Notice that ∆t0 is not a zero-measure time interval in the sense of domain measure equal to zero. For infinitesimal ∆t0 with zero-measure, eq. 12a is not valid, however ∆t0 is not well-defined. The order within addition matters. Addition for any two time-intervals means ∆t1 ‘addition’ ∆t2, writing A [∆t1, ∆t2]. It is possible to introduce the ‘addition inverse’ within time interval commutation relations, comment I, while in par. 2 and par. 5 applied is multiplication with scalar -1.
One defines multiplication M [∆t1, ∆t2] for any two time-intervals ∆t1 and ∆t2 from the introduction of time interval ‘multiplication unit’ ∆U, while the relevant event time interval remains ∆t, comment 2. Like with addition it is not clear immediately what multiplication means for the time interval only set. Within the time interval only set addition includes added domain, multiplication includes shared domain. Several properties for M are discussed in the following, where some obvious ones are already applied in par. 3.
Multiplication Linearity Theorem
Equations I*||∆t2 [∆t1] = M [∆t1, ∆t2] and D*||∆t2 [M [∆t1, ∆t2]] = A [∆t1, ∆t2] are valid for any two ∆t-quantities, including any two time-intervals ∆t1 and ∆t2 from the time interval only set.
The theorem means generalization of eq. 23 from commutation quantities to ∆t-quantities and time intervals. Applied are TE equilibrium and time interval derivatives. It is valid for any two ∆t-quantities, due to comment H for linear subsets, when proven for any two ∆t1, ∆t2 time intervals.
The specific Lorentz transformation TS defines ∆t’ from ∆t with cn’(∆t) = cn(∆t’), par. 4. Transformation TS and the specific change ∆t to ∆t’ such that Hamiltonian H remains time independent is introduced in (Hollestelle, 2021). Even when H time independent should imply ∆t = ∆t’ both infinite, it is assumed existence of case I, ∆t ≠ ∆t’. For transformation TS, with ∆t transformed to ∆t’, the multiplication linearity theorem is derived for ∆t1 = ∆t and ∆t2 = ∆t’, below in case I. For other transformations TN, ∆t1 to ∆t2, both time intervals are finite and there is H time dependent. With nonspecific TN, the linearity of ∆t2 with ∆t1 is assured, even when the linearity constants do not agree with any specific transformation TS, and this is included in Case I. Case II considers the no-reverse case.
Case I. Define cn’(∆t) = cn(∆t’), correspondence C2. Since due to TE equilibrium cn(∆t) and cn(∆t’) are linear in relevant event time interval, resp. ∆t and ∆t’ before and after transformation TS. From time interval equilibrium follows the linear transformation ∆t to ∆t’, and its reverse transformation. The reverse transformation ∆t’ is linear in cn(∆t) and thus also ∆t’ is linear in ∆t. This means the theorem is trivially valid for these ∆t1 = ∆t and ∆t2 = ∆t’. TS can be reversed unless it is a ‘constant’ transformation, not linear, and derivative D*||∆t for cn(∆t) or cn’(∆t) equals the time interval set ‘multiplication zero’ ∆U0, this is the no-reverse case.
When no specific transformation TS, with ∆t1 to ∆t2 = (∆t1)’, exists, a nonspecific TN transforms commutation constant cn(∆t1) to cn(∆t2) and ∆t1 to ∆t2, however ∆t2 ≠ (∆t1)’, and in terms of proof this is the same as for TS, while time dependence for H is not decisive. This means for both TN or TS the theorem is valid for any time interval ∆t1 and ∆t2, and for any ∆t-quantities being linear in ∆t, except for the no-reverse case.
An interpretation of change, time development, for ∆t is necessary. For changing ∆t the validity of the following is to be ensured: M’ [∆t1, ∆t’] = M’’ [∆t1, ∆t’’] = ∆t1, i. e. relevant event time interval ∆t’ changes to ∆t’’ while specific properties for M and A do not change and are defined with the relevant event time interval indication ∆t, one of these properties is ∆t = ∆U. It depends on what is meant to change: before change ∆t = ∆t’, after change ∆t = ∆t’’, where events with ∆t’ or ∆t’’ share properties, however not all properties, to assure change.
This makes sense since it agrees with the description of star source radiation propagation, including wave packet reduction during a measurement event, relevant event time interval ∆t, where a requirement is the metric surface measure remains invariant and equal to the propagation surface radiation energy, independent of relevant event time interval ∆t time development, (Hollestelle, 2021).
Case II. The no-reverse case
In this case a transformation TS changes ∆t1 to ∆t2 however the time interval commutation quantities remain invariant: cn(∆t1) = cn(∆t2), cn’ = cn, and this cannot be reversed one to one. Recall cn’ relates to cn with the specific transformation TS. Consider change of ∆t from ∆t1 to ∆t2 with distinct ∆t1 ≠ ∆t2, with ∆t = ∆t1 before change. Time development for invariant cn(∆t) implies A [cn(∆t2), cn(∆t1)iv] = M [+/-1. D*||∆t [cn(∆t)], A [∆t2, ∆t1iv]] = ∆t0, par. 2.
With D*||∆t [cn(∆t)] = ∆U0 for variable ∆t at ∆t1, one finds A [cn(∆t2), cn(∆t1)iv] = ∆U0. Then ∆U0 = ∆t0, i. e. ‘multiplication zero’ equals ‘addition zero’ for the time interval only set. Before change, cn(∆t1)iv = cn(∆t)iv = ∆tiv, and since ∆U0 has time interval domain measure zero, it follows cn(∆t2) = ∆U0 for any ∆t2, and is not well-defined, comment 14.
With D*||∆t [cn(∆t)] ≠ ∆U0 for variable ∆t at ∆t1, where A [∆t2, ∆t1] = A [∆t1, ∆t2] = ∆t2 and M [∆t1, ∆t2] = ∆t2. Started is from ∆t = ∆t1, with ∆t = ∆t2 after change.
It follows M [+/-1. D*||∆t [cn(∆t)], ∆t2] = ∆t0, time interval ‘multiplication unit’, for any ∆t2. One finds +/-1. D*||∆t [cn(∆t)] = +/-1. cn(∆t) = ∆t2i.
From relation M [cn(∆t), ∆t2] = ∆U, where cn(∆t) is linear in ∆t due to TE equilibrium, with some scalar constant a, and one finds cn(∆t) = a. ∆t, which implies a = 1. Solution for M [∆t, ∆t2] = ∆U before change is ∆t = ∆t2, disproving the above requirement for change of ∆t from ∆t1 to ∆t2 with ∆t1 ≠ ∆t2. This completes the derivation for the multiplication linearity theorem.
The validity of eq. 23 is assured for ∆t1 = cn(∆t) or cn’(∆t) from par. 5. From eq. 23, including the multiplication linearity theorem follow eq. 24 to 27.
24 |
I*||∆t [cn(∆t)] = A [cn(∆t), A [∆U, cn(∆t)]] = A [cn(∆t), cn(∆t)] |
I*||∆t [cn’(∆t)] = M [cn’(∆t), ∆t] = A [cn’(∆t), A [∆U, cn’(∆t)]] = A [cn’(∆t), cn’(∆t)]
A [a. ∆t1, ∆t] = D*||∆t [M [a. ∆t1, ∆t]] = D*||∆t [a. I*||∆t [∆t1]] = A [a. D*||∆t [I*||∆t [∆t1]], Rest(a)||∆t]
Not necessarily cn(∆t) follows the requirement of time interval asymmetry like ∆t itself for situations when H time dependent, and – 1. cn(∆t) can be valid however -1. ∆t is not. Scalar a is ‘moving to the left’ from I*||∆t without a non-zero factor Rest, however from D*||∆t only with ‘set rule’ eq. 20, including Rest(a)||∆t. From eq. 11, one can find I*||∆t [cn(∆t)] = A [cn(∆t), -1. cn’(∆t)].
Time development is equal for cn(∆t) and cn’(∆t), supported by the definition cn’(∆t) = cn(∆t’) and linearity of cn(∆t) in ∆t. For ∆t1 = cn(∆t) and ∆t2 = ∆t, there is Rest(a)||∆t = a. ∆U is non zero and for scalar a = 1 this is equal to ∆U = ∆t0, comment 12. Due to property A [∆t1, ∆U] = ∆t1 for any time interval ∆t1, and the second associative property for A, factor Rest(a)||∆t can be left out and the results for D*||∆t, and I*||∆t are exactly the same. For any scalar a and ∆t-quantity cn(∆t) linear with ∆t, one finds eq. 25 to 27.
25 |
a. cn(∆t) = D*||∆t [a. I*||∆t [cn(∆t)]] |
26 |
a. cn(∆t) = A [a. D*||∆t [I*||∆t [cn(∆t)]], Rest(a)||∆t] |
27 |
cn(∆t) = D*||∆t [I*||∆t [cn(∆t)]] |
Comment E. Time interval only wave equations and structure constants
The time interval only version of a plane wave depends on wave energy rather than one moment time quantities. I*||∆t and D*||∆t, and M and A, have the same results, due to results from comment D, and eq. 26 and 27 can be interpreted as second order derivative equations, since the multiplication linearity theorem is valid for any ∆t-quantity. The time interval equation sign is positive on both sides.
For the time interval version of QM field theory, where the wave momentum relation k = h. p, together with wave energy E = h. ν, remain valid, referred is to (Hollestelle, 2021). The above equations can only be a time interval only ‘wave’ equation version, when derived from the time interval field.
From combinations of commutation brackets, equal to scalar multiplications within the generator set of a group, structure constants depend on second derivatives, (Veltman, 1974; De Wit, Smith, 1986). Structure constants for the time interval set depend on D*||∆t [D*||∆t [M]], for some multiplication combination M, and on time development property, eq. 12b, M [∆t1, ∆t1] = ∆t1. From the discussion eq. 8, ∆N equals both addition and multiplication of the reciprocal pair of commutation quantities. Derivative D*||∆t [∆N] = A [cn(∆t), cn’(∆t)] = ∆N, and similarly the second derivative D*||∆t [D*||∆t [∆N]] = ∆N, and eq. 25 to 27 apply to ∆N. These eq. are exactly the requirements for time interval only structure constants.
Originating from multiplication within the time interval set, M = a1. ∆N = a1. M [cn(∆t), cn’(∆t)], including scalar a1, is solution for the time interval only wave equation eq. 25 and 27, and equals time interval only structure constant NCset = a1. ∆N. Combination M = a1. ∆N is a possible solution due to the D*||∆t derivative ‘set rule’ with Rest(a1)||∆t = a1. ∆U, for any scalar a1.
Second derivative invariants are specific Lorentz transformation TS invariants, since TS is a surface measure preserving transformation, unlike the usual Lorentz transformation TL. NCset = a1. ∆N is an invariant for TS. Both eq. 26 and 27, and Lorentz transformation TS, can be interpreted to be a ‘time interval only’ structure constant requirement.
The commutation constants form an n-pair and the existence of an overall equilibrium invariant, in this case ∆N = M [cn(∆t), cn’(∆t)], implies properties for structure constants NCset.
Comment 16. The dimension of the set decides the number of quantities within the n-pair for this set.
Comment 17. The n-pair, a number of n quantities, for the time interval only set is a reciprocal 2-pair, an ordinary pair of two quantities, since time development and the time interval only set are 1-dim. Generalization to different n is possible. There is n = 2 for 2 reciprocal time interval set commutation quantities cn(∆t) and cn’(∆t), eq. 11a, and the time interval only set is linear in ∆t, due to TE equilibrium, i. e. the multiplication linearity theorem. The equilibrium requirement, par. 4, implies a reduction for the number of structure constants from n to n - 1, and one independent time interval only structure constant remains, linear with ∆N = M [cn(∆t), cn’(∆t)].
Comment F. Relevant event time interval, simply measurable, simultaneity
One can define one moment time t, time interval ∆t = [tb, ta] and boundaries tb and ta within a 1-dim. time development, such that they agree with how time can be measured or counted. A time measurement is proposed to include counting towards ta in the future, while counting from tb in the past. The application of counting, a method of measuring, can relate quantities like one moment time coordinates with measurements. One can proof time intervals can be measured from within to beyond relevant event time interval ∆t, i. e. from ‘timely’ to ‘non-timely’ time intervals until a certain limit. Being ‘timely’, infinitesimal or ‘local’ in 3-space terms, means the time interval measure is additive, where ‘non-timely’, until a certain limit, means measurable however non-additive, non-linear. The definition of ‘timely’ and counting or measuring time intervals and one moment time coordinates tb and ta, is discussed in (Hollestelle, 2018, 2020).
Within the time interval description simultaneity is introduced for radiation emitted and ‘on the way’ during finite relevant event time interval ∆t, however only when ∆t is ‘simply measurable’, meaning measurable within one measurement. The radiation group-velocity is considered finite. It is argued the relevant event time interval ∆t is always simply measurable. Applied are results from (Hollestelle, 2020).
Assumed is a measurement event including the reduction of one wave packet. This is a non-stationary event, and change in wave energy E = T, kinetic wave particle energy, is argued to be ∆* E = ∆*T = -1. E = -1. T, (Merzbacher, 1970). The ∆* means energy change, not variation. For complete reduction of the wave packet introduced is the indication _, e. g. wave packet reduction time interval is ∆t_, with corresponding one moment time coordinate t_, and |t_| = |∆t_|. For |∆t_| or one moment time measure |t_| = |∆t_| < |∆t| this means ∆t is not simply measurable, i. e. not measurable within one measurement and one wave packet reduction.
Due to TE equilibrium, at ∆t = ∆t_, time interval derivative | D*||∆t [E] |= |E|. |∆t_i | = |T|. |t_i | = | D* [T] | at t = t_. By definition M [M [T, ∆t_i], ∆t_] = T = -1. ∆*T, and change in energy T is -1. |T|. |∆t_i|] = ∆*T and -1. |∆*T|. |∆t| = ∆*T by definition of ∆t = ∆ti, with solution |∆t_i| = |∆t|. One finds |t_| = |∆t| meaning ∆t is simply measurable and this confirms ∆t is the relevant event time interval, for any measurement event and wave packet reduction event. ∆t not necessarily is infinitesimal or ‘timely’. The solution |∆t_| = |∆t|, simply measurable requirement, is always fulfilled during any measurement event, i. e. wave packet reduction event, and relevant event time interval ∆t always is simply measurable.
Comment G. Noether charges and structure constants
According to set theory, structure constants are independent of set representation. Within the time interval only set, the multiplication linearity theorem implies linearity for multiplications, e. g. M [∆t1, ∆t2] = ∆t3 = a. ∆ta, providing linearity constants, structure constants, without introducing the generator set or representations. The canonical property is not valid due to existence of non-zero, time interval only, derivative ‘set-rule’ factors Rest(a)|t and Rest(a)||∆t, eq. 19 and 20.
For the time interval only set, structure constants are independent of the number of necessary and different ∆ta, i. e. whether the collection of time interval only set subsets of different ∆ta is reducible or irreducible, comment D and H. Similarly, the collection of ∆ta subsets is not completely determined by the structure constants. The time interval only set being 1-dim. means there is one independent subset, and one independent structure constant. Structure constants can relate to time development, e. g. dispersion during measurements, traditionally they are applied for particle scattering measurements. With quantities time interval ∆t, radiation wave energy h. ν, and group-velocity c(∆t), introduced is spherical symmetric wave propagation, within the time interval description in this paper, part I and part II. In the following linear multiplication scalars will be omitted.
Within the 1-dim. one moment time description, Noether charge NC = ∫||overall space dq [N0] and 3-dim. Noether current NU are related with a continuity equation integrated for overall space: ∫||overall space dq [d/dt. N0 + d/dq. NU] equals one moment time ‘addition zero’, (De Wit, Smith, 1986). The N0 and NU together are the Noether current in 4-dim. Then d/dt [NC] = ∫||overall space dq [d/dt. N0] equals one moment time ‘addition zero’ for any scalar multiplication, since for any Noether current NU always, including for scalar multiplication, the overall space integral equals < NU >||overall space equals one moment time ‘addition zero’.
Within the time interval only description, due to similarity of multiplication M and addition A, scalar multiplication invariance can relate, due to inferred similarity with the above argument, in general to a ‘gauge’ transformation, meaning usually within the one moment time description a time interval addition invariance. When scalar multiplication invariance can be interpreted with ‘gauge’ invariance, there is the possibility of ‘addition terms’ for the Noether current in 4-dim. This is supported by time interval only set properties eq. 12a and 12b, A [∆t1, ∆t1] = ∆t1, and M [∆t1, ∆t1] = ∆t1.
Within the time interval only set, from correspondence can be derived the time interval Noether charge and Noether current, NC equals N0 ~ NCset. Gauge transformations by itself are not the subject of this paper. For the time interval only set, in the following applied is; any Noether charge or structure constant multiplication scalar is disregarded, i. e. chosen equal to the time interval ‘multiplication unit’ ∆U.
A1. Measuring plane wave group-velocity c(∆t), the relevant event time interval is ∆t, and similarly ∆t is relevant event time interval for measuring ∆q, with c(∆t) and ∆q being ∆t-quantities linear in ∆t. There is c(∆t) = M [∆q, ∆ti] = D*||∆t [∆q], invariant with t during ∆t. Relation c(∆t) = M [c(∆t), ∆ti] = M [M [c(∆t), ∆ti], ∆ti] provides c(∆t) to be the second derivative linearity constant, i. e. NCset = c(∆t) is time interval only set structure constant. Similar arguments are valid for ∆N with result NCset = a1. ∆N, comment E. However, c(∆t) is not dimensionless.
There is, M [c(∆t), NCsetiv] = A [c(∆t), NCsetiv] = NCset, and it follows c(∆t) = ∆U and c(∆t) = NCset.
A2. This can be resolved by introducing a variable t-quantity h+ = 1/2 (∆*p. ∆*q + ∆*q. ∆*p), with variations ∆*, a possibly variable alternative for the constant of Planck h. Any constant, like h is, is both t-quantity and ∆t-quantity within the time interval description. For H time independent and ∆t symmetric and of infinite measure one recovers h+ = h. While considering non-interacting, dispersion free, star-source radiation propagation, it can however be claimed variations equal interval measures |∆*q| = |∆q| and |∆*p| = |∆p|, and h+ = M [E, ∆t] is a t-quantity and ∆t-quantity, linear in ∆t, for E equal to the invariant e.m. propagation surface field energy. Recall the time interval for E can differ from the relevant event time interval for c(∆t). The variations ∆*, variable h+ and field energy E are introduced in (Hollestelle, 2020, 2021).
The linearity relation, for c(∆t) from A1, is similar to E = M [h+, ∆ti], invariant during time development without interaction. Both h+ and c(∆t) are linear in ∆t, they are ∆t-quantities: E = M [h+, ∆ti], and c(∆t) = M [c(∆t), ∆ti].
Since trivially E = M [E, ∆ti] = M [M [E, ∆ti], ∆ti], both c(∆t) and E = M [E, ∆ti] can be considered linearity constants and time interval structure constants except for scalar multiplication. Related to different radiation properties, E or c(∆t) have different dimension and value, however, there is one independent structure constant, comment 16 and 17. Interaction, from t-quantity perspective, with ∆*q = ∆*q(t) or with h+ = h+(t), implies E and c(∆t) are one moment time quantities.
A3. The time interval invariants c_ = M [c(∆t)i, |c(∆t)|] for group-velocity and h. ν_ = M [(h. ν)i, |h. ν|] for radiation energy, result in dimensionless time interval structure constants DC and DN: DC = |M [c(∆t), c_]| = |c(∆t)|, and DN = |M [E, h. ν_]| = |h. ν|. There is an ambiguity in the sign of DC and DN. Only one of DC and DN can be independent, however not necessarily DC = DN.
A4. The usual one moment time Noether charge NC equals in value (a2. |h. ν|)^2, with a2 scalar, a result from (Hollestelle, 2021). Within the time interval only description a ∆t-quantity squared through multiplication is linear in the ∆t-quantity itself. Noether charges depend on derivative differences, and, comment E, this is an argument to expect any Noether charge is proportional with some structure constant.
A5. It is inferred the overall time interval and space interval averages for ∆N = A [cn(∆t), cn’(∆t)] are the same, par. 4. The average domain densities with ∆t the variable within the overall time interval only set, < D(cn, ∆t) >||∆t, and similar for cn’, are assumed to acquire lower and upper limits ∆U0 and ∆U resp., meaning cn(∆t) and cn’(∆t) acquire the same limits, par. 4. The limits follow from solving the wave equation for M, comment E, with the solution time interval structure constant M = NCset = a1. ∆N, for any scalar a1, including a1 = 1. The time interval wave equation is related to plane wave energy solutions |E| = |t0|, where t0 ~ ∆U, for ∆N.
A6. From eq. 8 there is, ∆N = M [∆N, A [< D(cn, ∆t) >||set, < D(cn, ∆t’) >||set]] = M [∆N, M [Dset, A [∆U, ∆U0]]], with solution ∆N = M [Dset, A [∆U, ∆U0]] = Dset. Invariant Dset is an approximation for the domain density averages. The averages are overall time interval set averages.
For one moment time Noether charge NC = a2. |h. ν| = a2. DN from (A3) and (A4), there is correspondence NC = N ~ ∆N = Dset. There is time interval structure constant NCset = a1. ∆N = M [|c(∆t)|, ∆U] from (A1) and (A5), with a1 scalar, and where NCset and ∆N belong to the linear subset for ∆t.
A7. Time interval Noether charge NCset = a1. ∆N ~ a2. DN, from (A3), (A4) and (A5), still including linearity constant a1, since there is only one ∆N linear subset.
A8. With dimensionless DC = M [c(∆t), c_] = |c(∆t)| equal to M [|c(∆t)|, ∆U], and from (A1) the time interval Noether charge DC = M [|c(∆t)|, ∆U] ~ NCset, and the group-velocity follows exactly from the commutation quantities, c(∆t) ~ a1. ∆N, for e.m. radiation, photons, there is c(∆t) equals light-velocity c. For all multiplication scalars equal to one, suggested above, c(∆t) ~ M [∆N, ∆U] = ∆N. From (A6) ∆N depends on Dset. In this case c(∆t) ~ M [Dset, ∆U] = Dset.
Dset depends on lower and upper limit of the domain densities, (A5). Disregarding the lower limit to be zero, this suggests there is an upper limit |Dset| < |∆U| for the group-velocity, i. e. a finite group-velocity, which obviously relates to relevant time interval ∆t to be finite. For photons, zero mass wave particles, a finite velocity c is expected. This result is independently derived within the time interval only description. However, an infinite velocity c is not consistent with observed e.m. phenomena from traditional experiments, even while however these usually are not discussed within the time interval only description.
A9. A new variable is complementary wave particle mass m, which can be zero or non-zero. Recall non-linearity factor Rest||∆t depends on time interval c(∆t) including on mass m. From Curie’s principle alone one can expect the difference, zero or non-zero mass, to be measurable or distinguishable from observables, depending on Noether charges and structure constants, e. g. measurable quantities energy or group-velocity.
Forthcoming part 2 includes a discussion of relevant mass m and mass density within a time interval only description of star-source radiation energy.
Comment H. Linear subsets
Multiplication result M [∆t1, ∆t2] = ∆t3 belongs to the time interval set due to the multiplication closure theorem, comment B. One assumes, TE equilibrium being maintained, any time interval including ∆t3 is linear in ∆t. This assumption remains to be verified for the validity of the multiplication closure theorem.
I. In (Hollestelle, 2020), and summarized in comment 6, defined are several transformations including scalar multiplication, with H remaining invariant. Due to the results in comment B including time interval multiplication interpreted with shared domain, with definition a. ∆ta = ∆t3 = M [∆t1, ∆t2], the multiplication a. ∆ta is a well-defined time interval.
II. Choose ∆t3’ = ∆ta, and one finds, when ∆ta’ = ∆t, the specific time interval ca’ and scalar a’, where ∆ta = M [ca’, ∆ta’] = M [ca’, ∆t] = a’. ∆t. The ∆ta’ define linear subsets, i. e. 1-dim. subsets a’. ∆t, for ∆t.
III. Choose newly ∆t3 = a. ∆ta = M [ca, ∆ta] and a. ∆ta = a. M [∆U, ∆ta] = M [a. ∆U, ∆ta] and this means multiplication with time interval ‘multiplication unit’ ∆U or with time interval ca both leave linear subsets defined by a. ∆ta for ∆ta, invariant, where linear subsets are defined by ∆ta for ∆t, step II. Applied is the symmetric first associative property for M, comment B. Indeed, it follows M [∆t1, ∆t2] = ∆t3 is linear in ∆t.
This confirms, in terms of linear subsets, time interval multiplication closure and the closure theorems from comment B.
Comment 23. Within the time interval description ∆t-quantity Noether charge ∆N = M [cn(∆t), cn’(∆t)] depends on multiplication and TE equilibrium, t-quantity one moment time coordinate t depends on addition and Lagrange equilibrium. Time interval description transformations ‘working to the right’ D* or D*||∆t can include multiplication with t or ti from usual commutation brackets, or can be non-linear due to the time interval derivative ‘set rule’ including factor Rest, eq. 19 and 20. Within the time interval description this means, non-linear events and linear events, in terms of H; time (in-)dependent events, or in terms of time intervals only; ∆t (a-)symmetric events, can be related by applying these transformations. For a transformation from H time dependent to H time independent or time interval ∆t asymmetric to symmetric reversible or not can be an issue.
Comment I. Addition commutation quantities and addition inverse
The time interval relations A [∆U0, ∆t0] = ∆t0 and ∆U0 = (1 + (- 1)). ∆t0 = A [∆t0, -1. ∆t0] seem contradictory. The confusion exists in applying -1. ∆t0 to mean ∆t0iv, the addition inverse, within time interval only addition equations like ∆U0 = A [∆t0, -1. ∆t0], and interpreting time interval only ‘addition zero’ ∆U0 to mean a difference including scalar -1. This originates from the one moment time description, with (1 + (- 1)). t0 = A [t0, -1. t0] to mean A [t0, t0iv], this description depending on vectors. Differently, in the time interval only description for any time interval ∆t2 the ‘addition zero’ depends on the addition inverse, defined with A [∆t2, ∆t2iv] = ∆U0.
To resolve this, one can consider ∆U0 has zero domain, comment 14, or consider there is extra degrees of freedom when quantities are subject to ‘moving to the other side of the equation-sign’, e. g. including scalar multiplication with -1. a, with scalar a, i. e. meaning introduction of addition commutation quantities. These can be joined to the time interval only multiplication commutation quantities, and similarly to Noether charges and structure constants, and this changes their number of degrees of freedom. The result with respect to the side of the equation-sign matters and can acquire different value, with dependence on the order of the involved time intervals.
To define addition commutation quantities, necessary is consistent correspondence with the time interval only set, including < t >||∆t ~ ∆U. However, correspondence can itself be subject to commutation quantities. A similar freedom seems to reside within rewriting Newton’s laws and equilibrium definitions depending on equation-sign side in a similar way, where equilibrium is defined from differences being equal to addition ‘zero’, (Hollestelle, 2020).