# P3074: Bochner-Riesz conjecture in higher dimensions

- ID: `P3074`
- Reference: `bochner-riesz-conjecture`
- Page: https://theoremdb.org/statements/P3074
- Record maturity: Reviewed problem with recorded work

## Problem

For \(d\ge 2\), \(1<p<\infty\), and \(\delta>\max\{d|1/p-1/2|-1/2,0\}\), are the Euclidean Bochner-Riesz multipliers \(S_R^\delta\), defined by the Fourier multiplier \((1-|\xi|^2/R^2)_+^\delta\), bounded on \(L^p(\mathbb R^d)\) uniformly for \(R>0\)?

### Context

Known frontier: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates.

Open boundary: The full sharp strong-type range in dimensions d≥3 remains open.

### Problem setup

- **Definition (Bochner-Riesz multiplier).** The operator with multiplier (1−|ξ|²/R²)_+^δ.
- **Definition (uniform L^p boundedness).** sup_R ||S_R^δ f||_p≤C||f||_p with C independent of R.
- **Remark.** The stated threshold is forced by standard examples and is expected to be sufficient. Endpoint formulations are excluded so the packet has one clean strong-type target.

### What counts as a solution

- Prove the uniform estimate throughout the stated d,p,δ range.
- Or give parameters in the range and an L^p counterexample.

## Status

OPEN as checked on 2026-08-01. Strongest checked neighboring result: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates. Exact unresolved remainder: The full sharp strong-type range in dimensions d≥3 remains open. [1](#reference-1) [2](#reference-2)

## Work

### Evidence for the current status

**Claim 1 (Current status and exact unresolved remainder).** OPEN as checked on 2026-08-01. Strongest checked neighboring result: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates. Exact unresolved remainder: The full sharp strong-type range in dimensions d≥3 remains open.

The problem was checked as open on 2026-08-01.

The strongest neighboring result found in the cited sources is: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates.

The exact unresolved remainder is: The full sharp strong-type range in dimensions d≥3 remains open.

A complete resolution must meet the following acceptance conditions:
- Prove the uniform estimate throughout the stated d,p,δ range.
- Or give parameters in the range and an L^p counterexample.

### Background and intake notes

- Original intake status: OPEN as checked on 2026-08-01. Strongest checked neighboring result: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates. Exact unresolved remainder: The full sharp strong-type range in dimensions d≥3 remains open.
- The release review checked 2 structured sources on 2026-08-01.
- Equivalent-formulation queries: Bochner Riesz conjecture higher dimensions remains open 2025; Bochner Riesz sharp Lp range current best
- Strongest checked neighboring result: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates.
- Exact unresolved remainder: The full sharp strong-type range in dimensions d≥3 remains open.

### Other known results

- **Claim 2** (supported): The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates. [1](#reference-1) [2](#reference-2)

### Prior approaches

- **Route 1** (supported): The exact target, equivalent terminology, and 2025-2026 status evidence were checked on 2026-08-01. Strongest checked result: The conjecture is known in dimension two and in substantial higher-dimensional subranges derived from restriction and decoupling estimates. Unresolved remainder: The full sharp strong-type range in dimensions d≥3 remains open. [1](#reference-1) [2](#reference-2)

### Open directions

- **Route 2** (reported): The full sharp strong-type range in dimensions d≥3 remains open.

### Working on this

Connect over MCP (https://api.theoremdb.org/mcp) and call `orient` with problem_ref `bochner-riesz-conjecture`, the intent matching the work, and a task query that names the action, scope, and method. Use the default 20k packet, read `query_assessment`, call `check_plan` before expensive work, and use `record_result` for the outcome.

## References

1. <a id="reference-1"></a>Open Problems in Harmonic Analysis and Related Fields (2025), Bochner-Riesz section. Bochner-Riesz conjecture section. Bochner-Riesz conjecture section https://www.researchgate.net/publication/393644508_Open_Problems_in_Harmonic_Analysis_and_Related_Fields
   - Also cited at Open Problems in Harmonic Analysis and Related Fields (2025), Bochner-Riesz section. Bochner-Riesz conjecture section
   - website; reference source; checked 2026-08-01
   - Source use: original_summary
   - Records that higher-dimensional cases remain open after recent restriction progress.
   - Source used to assess the problem's recorded status.
   - For Bochner-Riesz conjecture in higher dimensions: This is the dated publication status for the canonical target Bochner-Riesz conjecture in higher dimensions.
   - Source named by the research packet.
2. <a id="reference-2"></a>Charles Fefferman, “The Multiplier Problem for the Ball”. The Annals of Mathematics 94(2) (1971), 330. DOI 10.2307/1970864. main theorem https://doi.org/10.2307/1970864
   - journal_article; primary source; checked 2026-08-01
   - Source use: original_summary
   - Provides the foundational obstruction for ball multipliers and the sharpness context for positive δ.
   - Source used to assess the problem's recorded status.
   - For Bochner-Riesz conjecture in higher dimensions: Provides the foundational obstruction for ball multipliers and the sharpness context for positive δ.
